661157875 has 32 divisors (see below), whose sum is σ = 946707840. Its totient is φ = 451584000.

The previous prime is 661157867. The next prime is 661157909. The reversal of 661157875 is 578751166.

It is not a de Polignac number, because 661157875 - 2³ = 661157867 is a prime.

It is an unprimeable number.

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 in 31 ways as a sum of consecutive naturals, for example, 244531 + ... + 247219.

It is an arithmetic number, because the mean of its divisors is an integer number (29584620).

Almost surely, 2^661157875 is an apocalyptic number.

661157875 is a deficient number, since it is larger than the sum of its proper divisors (285549965).

661157875 is a wasteful number, since it uses less digits than its factorization.

661157875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992 (or 2982 counting only the distinct ones).

The product of its digits is 352800, while the sum is 46.

The square root of 661157875 is about 25712.9903939623. The cubic root of 661157875 is about 871.1676201607.

The spelling of 661157875 in words is "six hundred sixty-one million, one hundred fifty-seven thousand, eight hundred seventy-five".