31272021 has 32 divisors (see below), whose sum is σ = 51287040. Its totient is φ = 18673200.

The previous prime is 31272001. The next prime is 31272023. The reversal of 31272021 is 12027213.

It is not a de Polignac number, because 31272021 - 2⁹ = 31271509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31271985 and 31272003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31272023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20346 + ... + 21828.

It is an arithmetic number, because the mean of its divisors is an integer number (1602720).

Almost surely, 2^31272021 is an apocalyptic number.

It is an amenable number.

31272021 is a deficient number, since it is larger than the sum of its proper divisors (20015019).

31272021 is a wasteful number, since it uses less digits than its factorization.

31272021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574 (or 1568 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 31272021 is about 5592.1392150053. The cubic root of 31272021 is about 315.0542310258.

Adding to 31272021 its reverse (12027213), we get a palindrome (43299234).

The spelling of 31272021 in words is "thirty-one million, two hundred seventy-two thousand, twenty-one".