251349985 has 4 divisors (see below), whose sum is σ = 301619988. Its totient is φ = 201079984.

The previous prime is 251349983. The next prime is 251349997. The reversal of 251349985 is 589943152.

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

It can be written as a sum of positive squares in 2 ways, for example, as 44249104 + 207100881 = 6652^2 + 14391^2 .

It is a cyclic number.

It is not a de Polignac number, because 251349985 - 2¹ = 251349983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251349983) 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, 25134994 + ... + 25135003.

It is an arithmetic number, because the mean of its divisors is an integer number (75404997).

Almost surely, 2^251349985 is an apocalyptic number.

It is an amenable number.

251349985 is a deficient number, since it is larger than the sum of its proper divisors (50270003).

251349985 is an equidigital number, since it uses as much as digits as its factorization.

251349985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50270002.

The product of its digits is 388800, while the sum is 46.

The square root of 251349985 is about 15854.0210987623. The cubic root of 251349985 is about 631.0924063674.

The spelling of 251349985 in words is "two hundred fifty-one million, three hundred forty-nine thousand, nine hundred eighty-five".