251438563 has 2 divisors, whose sum is σ = 251438564. Its totient is φ = 251438562.

The previous prime is 251438557. The next prime is 251438573. The reversal of 251438563 is 365834152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251438563 - 2¹³ = 251430371 is a prime.

It is not a weakly prime, because it can be changed into another prime (251438513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125719281 + 125719282.

It is an arithmetic number, because the mean of its divisors is an integer number (125719282).

Almost surely, 2^251438563 is an apocalyptic number.

251438563 is a deficient number, since it is larger than the sum of its proper divisors (1).

251438563 is an equidigital number, since it uses as much as digits as its factorization.

251438563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86400, while the sum is 37.

The square root of 251438563 is about 15856.8144026472. The cubic root of 251438563 is about 631.1665318779.

The spelling of 251438563 in words is "two hundred fifty-one million, four hundred thirty-eight thousand, five hundred sixty-three".