157209331 has 4 divisors (see below), whose sum is σ = 157647600. Its totient is φ = 156771064.

The previous prime is 157209323. The next prime is 157209341. The reversal of 157209331 is 133902751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133902751 = 53 ⋅2526467.

It is a cyclic number.

It is not a de Polignac number, because 157209331 - 2³ = 157209323 is a prime.

It is a super-2 number, since 2×157209331² = 49429547506935122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 157209293 and 157209302.

It is not an unprimeable number, because it can be changed into a prime (157209341) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 218596 + ... + 219313.

It is an arithmetic number, because the mean of its divisors is an integer number (39411900).

Almost surely, 2^157209331 is an apocalyptic number.

157209331 is a deficient number, since it is larger than the sum of its proper divisors (438269).

157209331 is an equidigital number, since it uses as much as digits as its factorization.

157209331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438268.

The product of its (nonzero) digits is 5670, while the sum is 31.

The square root of 157209331 is about 12538.3145199026. The cubic root of 157209331 is about 539.7087260895.

The spelling of 157209331 in words is "one hundred fifty-seven million, two hundred nine thousand, three hundred thirty-one".