251555423 has 4 divisors (see below), whose sum is σ = 287491920. Its totient is φ = 215618928.

The previous prime is 251555419. The next prime is 251555431. The reversal of 251555423 is 324555152.

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

It is not a de Polignac number, because 251555423 - 2² = 251555419 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 251555423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251555413) 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, 17968238 + ... + 17968251.

It is an arithmetic number, because the mean of its divisors is an integer number (71872980).

Almost surely, 2^251555423 is an apocalyptic number.

251555423 is a deficient number, since it is larger than the sum of its proper divisors (35936497).

251555423 is an equidigital number, since it uses as much as digits as its factorization.

251555423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35936496.

The product of its digits is 30000, while the sum is 32.

The square root of 251555423 is about 15860.4988256990. The cubic root of 251555423 is about 631.2642982351.

The spelling of 251555423 in words is "two hundred fifty-one million, five hundred fifty-five thousand, four hundred twenty-three".