1231021 has 16 divisors (see below), whose sum is σ = 1477440. Its totient is φ = 1012480.

The previous prime is 1231003. The next prime is 1231039. The reversal of 1231021 is 1201321.

It is an interprime number because it is at equal distance from previous prime (1231003) and next prime (1231039).

It is a cyclic number.

It is not a de Polignac number, because 1231021 - 2¹³ = 1222829 is a prime.

It is a Duffinian number.

1231021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1230989 and 1231007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5310 + ... + 5536.

It is an arithmetic number, because the mean of its divisors is an integer number (92340).

2^1231021 is an apocalyptic number.

1231021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1231021 is a deficient number, since it is larger than the sum of its proper divisors (246419).

1231021 is a wasteful number, since it uses less digits than its factorization.

1231021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 1231021 is about 1109.5138575070. The cubic root of 1231021 is about 107.1737648821.

Adding to 1231021 its reverse (1201321), we get a palindrome (2432342).

The spelling of 1231021 in words is "one million, two hundred thirty-one thousand, twenty-one".