251251555452442 has 16 divisors (see below), whose sum is σ = 378590114278080. Its totient is φ = 125055004285728.

The previous prime is 251251555452433. The next prime is 251251555452449. The reversal of 251251555452442 is 244254555152152.

It is a self number, because there is not a number n which added to its sum of digits gives 251251555452442.

It is not an unprimeable number, because it can be changed into a prime (251251555452449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35122467 + ... + 41666422.

It is an arithmetic number, because the mean of its divisors is an integer number (23661882142380).

Almost surely, 2^{251251555452442} is an apocalyptic number.

251251555452442 is a deficient number, since it is larger than the sum of its proper divisors (127338558825638).

251251555452442 is a wasteful number, since it uses less digits than its factorization.

251251555452442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76796325.

The product of its digits is 16000000, while the sum is 52.

The spelling of 251251555452442 in words is "two hundred fifty-one trillion, two hundred fifty-one billion, five hundred fifty-five million, four hundred fifty-two thousand, four hundred forty-two".