681557501157 has 8 divisors (see below), whose sum is σ = 978646668384. Its totient is φ = 419420000688.

The previous prime is 681557501153. The next prime is 681557501173. The reversal of 681557501157 is 751105755186.

It is a happy number.

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

It is not a de Polignac number, because 681557501157 - 2² = 681557501153 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681557501153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8737916643 + ... + 8737916720.

It is an arithmetic number, because the mean of its divisors is an integer number (122330833548).

Almost surely, 2^681557501157 is an apocalyptic number.

It is an amenable number.

681557501157 is a deficient number, since it is larger than the sum of its proper divisors (297089167227).

681557501157 is a wasteful number, since it uses less digits than its factorization.

681557501157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17475833379.

The product of its (nonzero) digits is 1470000, while the sum is 51.

The spelling of 681557501157 in words is "six hundred eighty-one billion, five hundred fifty-seven million, five hundred one thousand, one hundred fifty-seven".