157217720 has 64 divisors (see below), whose sum is σ = 389219040. Its totient is φ = 57150720.

The previous prime is 157217689. The next prime is 157217741. The reversal of 157217720 is 27712751.

It is a super-2 number, since 2×157217720² = 49434822963996800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 51764 + ... + 54716.

Almost surely, 2^157217720 is an apocalyptic number.

157217720 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 157217720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194609520).

157217720 is an abundant number, since it is smaller than the sum of its proper divisors (232001320).

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

157217720 is a wasteful number, since it uses less digits than its factorization.

157217720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2997 (or 2971 counting only the distinct ones).

The product of its (nonzero) digits is 6860, while the sum is 32.

The square root of 157217720 is about 12538.6490500372. The cubic root of 157217720 is about 539.7183258928.

The spelling of 157217720 in words is "one hundred fifty-seven million, two hundred seventeen thousand, seven hundred twenty".