1011 has 4 divisors (see below), whose sum is σ = 1352. Its totient is φ = 672.

The previous prime is 1009. The next prime is 1013. The reversal of 1011 is 1101.

Adding to 1011 its reverse (1101), we get a palindrome (2112).

Multipling 1011 by its reverse (1101), we get a palindrome (1113111).

It can be divided in two parts, 10 and 11, that added together give a triangular number (21 = T_{6}).

1011 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1101 = 3 ⋅367.

It is an interprime number because it is at equal distance from previous prime (1009) and next prime (1013).

It is not a de Polignac number, because 1011 - 2^{1} = 1009 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (3), and also a Moran number because the ratio is a prime number: 337 = 1011 / (1 + 0 + 1 + 1).

It is a D-number.

It is a Duffinian number.

1011 is an undulating number in base 16.

1011 is a modest number, since divided by 11 gives 10 as remainder.

1011 is a lucky number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to *n*+sod(*n*) for *n* = 987 and 1005.

It is not an unprimeable number, because it can be changed into a prime (1013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166 + ... + 171.

It is an arithmetic number, because the mean of its divisors is an integer number (338).

1011 is a deficient number, since it is larger than the sum of its proper divisors (341).

1011 is an equidigital number, since it uses as much as digits as its factorization.

1011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340.

The product of its (nonzero) digits is 1, while the sum is 3.

The square root of 1011 is about 31.7962261912. The cubic root of 1011 is about 10.0365330379.

The spelling of 1011 in words is "one thousand, eleven", and thus it is an iban number.

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