156128507161 has 27 divisors (see below), whose sum is σ = 182387299773. Its totient is φ = 133522667520.

The previous prime is 156128507137. The next prime is 156128507173. The reversal of 156128507161 is 161705821651.

The square root of 156128507161 is 395131.

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 30670867161 + 125457640000 = 175131^2 + 354200^2 .

It is not a de Polignac number, because 156128507161 - 2⁷ = 156128507033 is a prime.

It is a super-2 number, since 2×156128507161² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (156128507111) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 73888441 + ... + 73890553.

Almost surely, 2^156128507161 is an apocalyptic number.

156128507161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

156128507161 is the 395131-st square number.

156128507161 is the 197566-th centered octagonal number.

It is an amenable number.

156128507161 is a deficient number, since it is larger than the sum of its proper divisors (26258792612).

156128507161 is an frugal number, since it uses more digits than its factorization.

156128507161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4282 (or 2141 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 43.

The spelling of 156128507161 in words is "one hundred fifty-six billion, one hundred twenty-eight million, five hundred seven thousand, one hundred sixty-one".