166501557 has 12 divisors (see below), whose sum is σ = 248795820. Its totient is φ = 107173248.

The previous prime is 166501493. The next prime is 166501583. The reversal of 166501557 is 755105661.

It can be written as a sum of positive squares in 2 ways, for example, as 62583921 + 103917636 = 7911^2 + 10194^2 .

It is not a de Polignac number, because 166501557 - 2⁶ = 166501493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166501597) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 318708 + ... + 319229.

It is an arithmetic number, because the mean of its divisors is an integer number (20732985).

Almost surely, 2^166501557 is an apocalyptic number.

It is an amenable number.

166501557 is a deficient number, since it is larger than the sum of its proper divisors (82294263).

166501557 is a wasteful number, since it uses less digits than its factorization.

166501557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637972 (or 637969 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 36.

The square root of 166501557 is about 12903.5482329474. The cubic root of 166501557 is about 550.1394214039.

The spelling of 166501557 in words is "one hundred sixty-six million, five hundred one thousand, five hundred fifty-seven".