157721730 has 16 divisors (see below), whose sum is σ = 378532224. Its totient is φ = 42059120.

The previous prime is 157721719. The next prime is 157721731. The reversal of 157721730 is 37127751.

It is a super-2 number, since 2×157721730² = 49752288228385800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 157721691 and 157721700.

It is not an unprimeable number, because it can be changed into a prime (157721731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2628666 + ... + 2628725.

It is an arithmetic number, because the mean of its divisors is an integer number (23658264).

Almost surely, 2^157721730 is an apocalyptic number.

157721730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

157721730 is an abundant number, since it is smaller than the sum of its proper divisors (220810494).

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

157721730 is a wasteful number, since it uses less digits than its factorization.

157721730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5257401.

The product of its (nonzero) digits is 10290, while the sum is 33.

The square root of 157721730 is about 12558.7312257250. The cubic root of 157721730 is about 540.2944553202.

The spelling of 157721730 in words is "one hundred fifty-seven million, seven hundred twenty-one thousand, seven hundred thirty".