157221138 has 8 divisors (see below), whose sum is σ = 314442288. Its totient is φ = 52407044.

The previous prime is 157221133. The next prime is 157221149. The reversal of 157221138 is 831122751.

It is a sphenic number, since it is the product of 3 distinct primes.

157221138 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (157221133) 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 3 ways as a sum of consecutive naturals, for example, 13101756 + ... + 13101767.

It is an arithmetic number, because the mean of its divisors is an integer number (39305286).

Almost surely, 2^157221138 is an apocalyptic number.

157221138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

157221138 is a wasteful number, since it uses less digits than its factorization.

157221138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26203528.

The product of its digits is 3360, while the sum is 30.

The square root of 157221138 is about 12538.7853478716. The cubic root of 157221138 is about 539.7222371226.

Adding to 157221138 its reverse (831122751), we get a palindrome (988343889).

The spelling of 157221138 in words is "one hundred fifty-seven million, two hundred twenty-one thousand, one hundred thirty-eight".