37661140525721 has 2 divisors, whose sum is σ = 37661140525722. Its totient is φ = 37661140525720.

The previous prime is 37661140525639. The next prime is 37661140525819. The reversal of 37661140525721 is 12752504116673.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20143266015625 + 17517874510096 = 4488125^2 + 4185436^2 .

It is a cyclic number.

It is not a de Polignac number, because 37661140525721 - 2¹⁴ = 37661140509337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 37661140525721.

It is not a weakly prime, because it can be changed into another prime (37661140521721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18830570262860 + 18830570262861.

It is an arithmetic number, because the mean of its divisors is an integer number (18830570262861).

Almost surely, 2^{37661140525721} is an apocalyptic number.

It is an amenable number.

37661140525721 is a deficient number, since it is larger than the sum of its proper divisors (1).

37661140525721 is an equidigital number, since it uses as much as digits as its factorization.

37661140525721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2116800, while the sum is 50.

The spelling of 37661140525721 in words is "thirty-seven trillion, six hundred sixty-one billion, one hundred forty million, five hundred twenty-five thousand, seven hundred twenty-one".