31525213 has 2 divisors, whose sum is σ = 31525214. Its totient is φ = 31525212.

The previous prime is 31525211. The next prime is 31525229. The reversal of 31525213 is 31252513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21040569 + 10484644 = 4587^2 + 3238^2 .

It is an emirp because it is prime and its reverse (31252513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31525213 - 2¹ = 31525211 is a prime.

Together with 31525211, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31525211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15762606 + 15762607.

It is an arithmetic number, because the mean of its divisors is an integer number (15762607).

Almost surely, 2^31525213 is an apocalyptic number.

It is an amenable number.

31525213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31525213 is an equidigital number, since it uses as much as digits as its factorization.

31525213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 900, while the sum is 22.

The square root of 31525213 is about 5614.7317834426. The cubic root of 31525213 is about 315.9022189853.

Adding to 31525213 its reverse (31252513), we get a palindrome (62777726).

The spelling of 31525213 in words is "thirty-one million, five hundred twenty-five thousand, two hundred thirteen".