31261215652361 has 4 divisors (see below), whose sum is σ = 31261243207572. Its totient is φ = 31261188097152.

The previous prime is 31261215652301. The next prime is 31261215652397. The reversal of 31261215652361 is 16325651216213.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16997941596736 + 14263274055625 = 4122856^2 + 3776675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31261215652361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31261215652301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11999360 + ... + 14370353.

It is an arithmetic number, because the mean of its divisors is an integer number (7815310801893).

Almost surely, 2^{31261215652361} is an apocalyptic number.

It is an amenable number.

31261215652361 is a deficient number, since it is larger than the sum of its proper divisors (27555211).

31261215652361 is a wasteful number, since it uses less digits than its factorization.

31261215652361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27555210.

The product of its digits is 388800, while the sum is 44.

Adding to 31261215652361 its reverse (16325651216213), we get a palindrome (47586866868574).

The spelling of 31261215652361 in words is "thirty-one trillion, two hundred sixty-one billion, two hundred fifteen million, six hundred fifty-two thousand, three hundred sixty-one".