31828021 has 16 divisors (see below), whose sum is σ = 35245440. Its totient is φ = 28607040.

The previous prime is 31828019. The next prime is 31828061. The reversal of 31828021 is 12082813.

It is a cyclic number.

It is not a de Polignac number, because 31828021 - 2¹ = 31828019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31828061) 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 15 ways as a sum of consecutive naturals, for example, 75391 + ... + 75811.

It is an arithmetic number, because the mean of its divisors is an integer number (2202840).

Almost surely, 2^31828021 is an apocalyptic number.

It is an amenable number.

31828021 is a deficient number, since it is larger than the sum of its proper divisors (3417419).

31828021 is a wasteful number, since it uses less digits than its factorization.

31828021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 31828021 is about 5641.6328310162. The cubic root of 31828021 is about 316.9104391944.

The spelling of 31828021 in words is "thirty-one million, eight hundred twenty-eight thousand, twenty-one".