1012121111 has 4 divisors (see below), whose sum is σ = 1012720632. Its totient is φ = 1011521592.

The previous prime is 1012121081. The next prime is 1012121113. The reversal of 1012121111 is 1111212101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1111212101 = 103 ⋅10788467.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1012121111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1012121092 and 1012121101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1012121113) 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, 297221 + ... + 300606.

It is an arithmetic number, because the mean of its divisors is an integer number (253180158).

Almost surely, 2^1012121111 is an apocalyptic number.

1012121111 is a deficient number, since it is larger than the sum of its proper divisors (599521).

1012121111 is an equidigital number, since it uses as much as digits as its factorization.

1012121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599520.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 1012121111 is about 31813.8509300588. The cubic root of 1012121111 is about 1004.0241547894.

Adding to 1012121111 its reverse (1111212101), we get a palindrome (2123333212).

It can be divided in two parts, 101 and 2121111, that added together give a palindrome (2121212).

The spelling of 1012121111 in words is "one billion, twelve million, one hundred twenty-one thousand, one hundred eleven".