157871923561 has 27 divisors (see below), whose sum is σ = 178066396837. Its totient is φ = 139860512000.

The previous prime is 157871923537. The next prime is 157871923591. The reversal of 157871923561 is 165329178751.

The square root of 157871923561 is 397331.

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

It can be written as a sum of positive squares in 4 ways, for example, as 99520689961 + 58351233600 = 315469^2 + 241560^2 .

It is not a de Polignac number, because 157871923561 - 2¹⁷ = 157871792489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157871923511) 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 26 ways as a sum of consecutive naturals, for example, 179195841 + ... + 179196721.

Almost surely, 2^157871923561 is an apocalyptic number.

157871923561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

157871923561 is the 397331-st square number.

157871923561 is the 198666-th centered octagonal number.

It is an amenable number.

157871923561 is a deficient number, since it is larger than the sum of its proper divisors (20194473276).

157871923561 is an frugal number, since it uses more digits than its factorization.

157871923561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1866 (or 933 counting only the distinct ones).

The product of its digits is 3175200, while the sum is 55.

The spelling of 157871923561 in words is "one hundred fifty-seven billion, eight hundred seventy-one million, nine hundred twenty-three thousand, five hundred sixty-one".