231697553 has 4 divisors (see below), whose sum is σ = 232088868. Its totient is φ = 231306240.

The previous prime is 231697549. The next prime is 231697567. The reversal of 231697553 is 355796132.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78730129 + 152967424 = 8873^2 + 12368^2 .

It is a cyclic number.

It is not a de Polignac number, because 231697553 - 2² = 231697549 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 231697553.

It is not an unprimeable number, because it can be changed into a prime (231697513) 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, 194768 + ... + 195953.

It is an arithmetic number, because the mean of its divisors is an integer number (58022217).

Almost surely, 2^231697553 is an apocalyptic number.

It is an amenable number.

231697553 is a deficient number, since it is larger than the sum of its proper divisors (391315).

231697553 is an equidigital number, since it uses as much as digits as its factorization.

231697553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391314.

The product of its digits is 170100, while the sum is 41.

The square root of 231697553 is about 15221.6146646800. The cubic root of 231697553 is about 614.1962337896.

The spelling of 231697553 in words is "two hundred thirty-one million, six hundred ninety-seven thousand, five hundred fifty-three".