31040525161721 has 2 divisors, whose sum is σ = 31040525161722. Its totient is φ = 31040525161720.

The previous prime is 31040525161717. The next prime is 31040525161729. The reversal of 31040525161721 is 12716152504013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19916539212025 + 11123985949696 = 4462795^2 + 3335264^2 .

It is a cyclic number.

It is not a de Polignac number, because 31040525161721 - 2² = 31040525161717 is a prime.

It is not a weakly prime, because it can be changed into another prime (31040525161729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15520262580860 + 15520262580861.

It is an arithmetic number, because the mean of its divisors is an integer number (15520262580861).

Almost surely, 2^{31040525161721} is an apocalyptic number.

It is an amenable number.

31040525161721 is a deficient number, since it is larger than the sum of its proper divisors (1).

31040525161721 is an equidigital number, since it uses as much as digits as its factorization.

31040525161721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50400, while the sum is 38.

Adding to 31040525161721 its reverse (12716152504013), we get a palindrome (43756677665734).

The spelling of 31040525161721 in words is "thirty-one trillion, forty billion, five hundred twenty-five million, one hundred sixty-one thousand, seven hundred twenty-one".