2157664658 has 4 divisors (see below), whose sum is σ = 3236496990. Its totient is φ = 1078832328.

The previous prime is 2157664627. The next prime is 2157664727. The reversal of 2157664658 is 8564667512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1953374809 + 204289849 = 44197^2 + 14293^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 539416163 + ... + 539416166.

Almost surely, 2^2157664658 is an apocalyptic number.

2157664658 is a deficient number, since it is larger than the sum of its proper divisors (1078832332).

2157664658 is a wasteful number, since it uses less digits than its factorization.

2157664658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078832331.

The product of its digits is 2419200, while the sum is 50.

The square root of 2157664658 is about 46450.6690802189. The cubic root of 2157664658 is about 1292.1947810409.

The spelling of 2157664658 in words is "two billion, one hundred fifty-seven million, six hundred sixty-four thousand, six hundred fifty-eight".