156991680 has 252 divisors, whose sum is σ = 573676272. Its totient is φ = 39398400.

The previous prime is 156991649. The next prime is 156991693. The reversal of 156991680 is 86199651.

156991680 is a `hidden beast` number, since 1 + 569 + 9 + 1 + 6 + 80 = 666.

It is a super-3 number, since 3×156991680³ (a number of 26 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1039605 + ... + 1039755.

Almost surely, 2^156991680 is an apocalyptic number.

156991680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 156991680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286838136).

156991680 is an abundant number, since it is smaller than the sum of its proper divisors (416684592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

156991680 is a wasteful number, since it uses less digits than its factorization.

156991680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 156991680 is about 12529.6320775991. The cubic root of 156991680 is about 539.4595415677.

The spelling of 156991680 in words is "one hundred fifty-six million, nine hundred ninety-one thousand, six hundred eighty".