31532021 has 2 divisors, whose sum is σ = 31532022. Its totient is φ = 31532020.

The previous prime is 31532003. The next prime is 31532063. The reversal of 31532021 is 12023513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30747025 + 784996 = 5545^2 + 886^2 .

It is an emirp because it is prime and its reverse (12023513) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31532021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31532071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15766010 + 15766011.

It is an arithmetic number, because the mean of its divisors is an integer number (15766011).

Almost surely, 2^31532021 is an apocalyptic number.

It is an amenable number.

31532021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31532021 is an equidigital number, since it uses as much as digits as its factorization.

31532021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 31532021 is about 5615.3380129784. The cubic root of 31532021 is about 315.9249574783.

Adding to 31532021 its reverse (12023513), we get a palindrome (43555534).

The spelling of 31532021 in words is "thirty-one million, five hundred thirty-two thousand, twenty-one".