157909 has 4 divisors (see below), whose sum is σ = 166240. Its totient is φ = 149580.

The previous prime is 157907. The next prime is 157931. The reversal of 157909 is 909751.

157909 = 82² + 83² + ... + 100².

157909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 909751 = 43 ⋅21157.

It is a cyclic number.

It is not a de Polignac number, because 157909 - 2¹ = 157907 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4137 + ... + 4174.

It is an arithmetic number, because the mean of its divisors is an integer number (41560).

2¹⁵⁷⁹⁰⁹ is an apocalyptic number.

157909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

157909 is a deficient number, since it is larger than the sum of its proper divisors (8331).

157909 is an equidigital number, since it uses as much as digits as its factorization.

157909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8330.

The product of its (nonzero) digits is 2835, while the sum is 31.

The square root of 157909 is about 397.3776541277. The cubic root of 157909 is about 54.0508209260.

The spelling of 157909 in words is "one hundred fifty-seven thousand, nine hundred nine".