31011021 has 24 divisors (see below), whose sum is σ = 47503040. Its totient is φ = 19440000.

The previous prime is 31011011. The next prime is 31011089. The reversal of 31011021 is 12011013.

It is not a de Polignac number, because 31011021 - 2¹⁰ = 31009997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31010994 and 31011012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31011011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25221 + ... + 26421.

Almost surely, 2^31011021 is an apocalyptic number.

It is an amenable number.

31011021 is a deficient number, since it is larger than the sum of its proper divisors (16492019).

31011021 is a wasteful number, since it uses less digits than its factorization.

31011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377 (or 1374 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 31011021 is about 5568.7539898976. The cubic root of 31011021 is about 314.1752878781.

Adding to 31011021 its reverse (12011013), we get a palindrome (43022034).

The spelling of 31011021 in words is "thirty-one million, eleven thousand, twenty-one".