521617665400761 has 8 divisors (see below), whose sum is σ = 695490347642464. Its totient is φ = 347745046713120.

The previous prime is 521617665400753. The next prime is 521617665400813. The reversal of 521617665400761 is 167004566716125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 521617665400761 - 2³ = 521617665400753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521617660400761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8696925 + ... + 33449541.

It is an arithmetic number, because the mean of its divisors is an integer number (86936293455308).

Almost surely, 2^{521617665400761} is an apocalyptic number.

It is an amenable number.

521617665400761 is a deficient number, since it is larger than the sum of its proper divisors (173872682241703).

521617665400761 is a wasteful number, since it uses less digits than its factorization.

521617665400761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31777031.

The product of its (nonzero) digits is 12700800, while the sum is 57.

The spelling of 521617665400761 in words is "five hundred twenty-one trillion, six hundred seventeen billion, six hundred sixty-five million, four hundred thousand, seven hundred sixty-one".