157691909 has 8 divisors (see below), whose sum is σ = 161293440. Its totient is φ = 154100736.

The previous prime is 157691857. The next prime is 157691917. The reversal of 157691909 is 909196751.

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

It is a cyclic number.

It is not a de Polignac number, because 157691909 - 2¹⁶ = 157626373 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157691929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33962 + ... + 38324.

It is an arithmetic number, because the mean of its divisors is an integer number (20161680).

Almost surely, 2^157691909 is an apocalyptic number.

It is an amenable number.

157691909 is a deficient number, since it is larger than the sum of its proper divisors (3601531).

157691909 is an equidigital number, since it uses as much as digits as its factorization.

157691909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5179.

The product of its (nonzero) digits is 153090, while the sum is 47.

The square root of 157691909 is about 12557.5439079463. The cubic root of 157691909 is about 540.2604013854.

The spelling of 157691909 in words is "one hundred fifty-seven million, six hundred ninety-one thousand, nine hundred nine".