158737699561 has 45 divisors (see below), whose sum is σ = 190306861271. Its totient is φ = 132396227376.

The previous prime is 158737699451. The next prime is 158737699609. The reversal of 158737699561 is 165996737851.

The square root of 158737699561 is 398419.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 144396200025 + 14341499536 = 379995^2 + 119756^2 .

It is not a de Polignac number, because 158737699561 - 2³⁵ = 124377961193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (158737699361) 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 44 ways as a sum of consecutive naturals, for example, 917558871 + ... + 917559043.

Almost surely, 2^158737699561 is an apocalyptic number.

158737699561 is the 398419-th square number.

158737699561 is the 199210-th centered octagonal number.

It is an amenable number.

158737699561 is a deficient number, since it is larger than the sum of its proper divisors (31569161710).

158737699561 is an frugal number, since it uses more digits than its factorization.

158737699561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468 (or 227 counting only the distinct ones).

The product of its digits is 85730400, while the sum is 67.

The spelling of 158737699561 in words is "one hundred fifty-eight billion, seven hundred thirty-seven million, six hundred ninety-nine thousand, five hundred sixty-one".