31436521 has 2 divisors, whose sum is σ = 31436522. Its totient is φ = 31436520.

The previous prime is 31436477. The next prime is 31436567. The reversal of 31436521 is 12563413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31304025 + 132496 = 5595^2 + 364^2 .

It is an emirp because it is prime and its reverse (12563413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31436521 - 2¹³ = 31428329 is a prime.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (31436021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15718260 + 15718261.

It is an arithmetic number, because the mean of its divisors is an integer number (15718261).

Almost surely, 2^31436521 is an apocalyptic number.

It is an amenable number.

31436521 is a deficient number, since it is larger than the sum of its proper divisors (1).

31436521 is an equidigital number, since it uses as much as digits as its factorization.

31436521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 25.

The square root of 31436521 is about 5606.8280694168. The cubic root of 31436521 is about 315.6056910842.

Adding to 31436521 its reverse (12563413), we get a palindrome (43999934).

The spelling of 31436521 in words is "thirty-one million, four hundred thirty-six thousand, five hundred twenty-one".