251456831421 has 16 divisors (see below), whose sum is σ = 346105878528. Its totient is φ = 162223297200.

The previous prime is 251456831419. The next prime is 251456831449. The reversal of 251456831421 is 124138654152.

It is not a de Polignac number, because 251456831421 - 2¹ = 251456831419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251456831411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3006450 + ... + 3088956.

It is an arithmetic number, because the mean of its divisors is an integer number (21631617408).

Almost surely, 2^251456831421 is an apocalyptic number.

It is an amenable number.

251456831421 is a deficient number, since it is larger than the sum of its proper divisors (94649047107).

251456831421 is a wasteful number, since it uses less digits than its factorization.

251456831421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115312.

The product of its digits is 230400, while the sum is 42.

The spelling of 251456831421 in words is "two hundred fifty-one billion, four hundred fifty-six million, eight hundred thirty-one thousand, four hundred twenty-one".