231906557 has 4 divisors (see below), whose sum is σ = 234074016. Its totient is φ = 229739100.

The previous prime is 231906553. The next prime is 231906569. The reversal of 231906557 is 755609132.

It is a happy number.

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 231906557 - 2² = 231906553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231906557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231906551) 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, 1083569 + ... + 1083782.

It is an arithmetic number, because the mean of its divisors is an integer number (58518504).

Almost surely, 2^231906557 is an apocalyptic number.

It is an amenable number.

231906557 is a deficient number, since it is larger than the sum of its proper divisors (2167459).

231906557 is a wasteful number, since it uses less digits than its factorization.

231906557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2167458.

The product of its (nonzero) digits is 56700, while the sum is 38.

The square root of 231906557 is about 15228.4784860471. The cubic root of 231906557 is about 614.3808579380.

The spelling of 231906557 in words is "two hundred thirty-one million, nine hundred six thousand, five hundred fifty-seven".