31523037121 has 2 divisors, whose sum is σ = 31523037122. Its totient is φ = 31523037120.

The previous prime is 31523037109. The next prime is 31523037131. The reversal of 31523037121 is 12173032513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16254975025 + 15268062096 = 127495^2 + 123564^2 .

It is a cyclic number.

It is not a de Polignac number, because 31523037121 - 2⁹ = 31523036609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31523037121.

It is not a weakly prime, because it can be changed into another prime (31523037131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15761518560 + 15761518561.

It is an arithmetic number, because the mean of its divisors is an integer number (15761518561).

Almost surely, 2^31523037121 is an apocalyptic number.

It is an amenable number.

31523037121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31523037121 is an equidigital number, since it uses as much as digits as its factorization.

31523037121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 28.

Adding to 31523037121 its reverse (12173032513), we get a palindrome (43696069634).

The spelling of 31523037121 in words is "thirty-one billion, five hundred twenty-three million, thirty-seven thousand, one hundred twenty-one".