231778641 has 4 divisors (see below), whose sum is σ = 309038192. Its totient is φ = 154519092.

The previous prime is 231778601. The next prime is 231778681. The reversal of 231778641 is 146877132.

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 an interprime number because it is at equal distance from previous prime (231778601) and next prime (231778681).

It is not a de Polignac number, because 231778641 - 2⁷ = 231778513 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 231778641.

It is not an unprimeable number, because it can be changed into a prime (231778601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38629771 + ... + 38629776.

It is an arithmetic number, because the mean of its divisors is an integer number (77259548).

Almost surely, 2^231778641 is an apocalyptic number.

It is an amenable number.

231778641 is a deficient number, since it is larger than the sum of its proper divisors (77259551).

231778641 is an equidigital number, since it uses as much as digits as its factorization.

231778641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77259550.

The product of its digits is 56448, while the sum is 39.

The square root of 231778641 is about 15224.2780124379. The cubic root of 231778641 is about 614.2678762313.

The spelling of 231778641 in words is "two hundred thirty-one million, seven hundred seventy-eight thousand, six hundred forty-one".