31242921 has 8 divisors (see below), whose sum is σ = 42543744. Its totient is φ = 20385360.

The previous prime is 31242907. The next prime is 31242931. The reversal of 31242921 is 12924213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31242921 - 2⁷ = 31242793 is a prime.

It is a super-2 number, since 2×31242921² = 1952240225224482, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31242891 and 31242900.

It is not an unprimeable number, because it can be changed into a prime (31242931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110650 + ... + 110931.

It is an arithmetic number, because the mean of its divisors is an integer number (5317968).

Almost surely, 2^31242921 is an apocalyptic number.

It is an amenable number.

31242921 is a deficient number, since it is larger than the sum of its proper divisors (11300823).

31242921 is a wasteful number, since it uses less digits than its factorization.

31242921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221631.

The product of its digits is 864, while the sum is 24.

The square root of 31242921 is about 5589.5367428795. The cubic root of 31242921 is about 314.9564767279.

The spelling of 31242921 in words is "thirty-one million, two hundred forty-two thousand, nine hundred twenty-one".