157511993 has 4 divisors (see below), whose sum is σ = 160863360. Its totient is φ = 154160628.

The previous prime is 157511971. The next prime is 157511999. The reversal of 157511993 is 399115751.

157511993 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.

It is a cyclic number.

It is not a de Polignac number, because 157511993 - 2²⁶ = 90403129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 157511993.

It is not an unprimeable number, because it can be changed into a prime (157511999) 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, 1675613 + ... + 1675706.

It is an arithmetic number, because the mean of its divisors is an integer number (40215840).

Almost surely, 2^157511993 is an apocalyptic number.

It is an amenable number.

157511993 is a deficient number, since it is larger than the sum of its proper divisors (3351367).

157511993 is an equidigital number, since it uses as much as digits as its factorization.

157511993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3351366.

The product of its digits is 42525, while the sum is 41.

The square root of 157511993 is about 12550.3782014727. The cubic root of 157511993 is about 540.0548561099.

The spelling of 157511993 in words is "one hundred fifty-seven million, five hundred eleven thousand, nine hundred ninety-three".