31021121 has 4 divisors (see below), whose sum is σ = 31038000. Its totient is φ = 31004244.

The previous prime is 31021093. The next prime is 31021127. The reversal of 31021121 is 12112013.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31021121 - 2²² = 26826817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31021127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5291 + ... + 9488.

It is an arithmetic number, because the mean of its divisors is an integer number (7759500).

Almost surely, 2^31021121 is an apocalyptic number.

It is an amenable number.

31021121 is a deficient number, since it is larger than the sum of its proper divisors (16879).

31021121 is a wasteful number, since it uses less digits than its factorization.

31021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16878.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 31021121 is about 5569.6607616622. The cubic root of 31021121 is about 314.2093921618.

Adding to 31021121 its reverse (12112013), we get a palindrome (43133134).

The spelling of 31021121 in words is "thirty-one million, twenty-one thousand, one hundred twenty-one".