157661661 has 16 divisors (see below), whose sum is σ = 218592000. Its totient is φ = 100957248.

The previous prime is 157661659. The next prime is 157661681. The reversal of 157661661 is 166166751.

It is not a de Polignac number, because 157661661 - 2¹ = 157661659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157661681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12540 + ... + 21738.

It is an arithmetic number, because the mean of its divisors is an integer number (13662000).

Almost surely, 2^157661661 is an apocalyptic number.

It is an amenable number.

157661661 is a deficient number, since it is larger than the sum of its proper divisors (60930339).

157661661 is a wasteful number, since it uses less digits than its factorization.

157661661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9428.

The product of its digits is 45360, while the sum is 39.

The square root of 157661661 is about 12556.3394745443. The cubic root of 157661661 is about 540.2258554540.

The spelling of 157661661 in words is "one hundred fifty-seven million, six hundred sixty-one thousand, six hundred sixty-one".