251898985 has 8 divisors (see below), whose sum is σ = 325531080. Its totient is φ = 186017664.

The previous prime is 251898973. The next prime is 251898989. The reversal of 251898985 is 589898152.

It is a happy number.

251898985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 23193856 + 228705129 = 4816^2 + 15123^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 251898985 - 2¹⁵ = 251866217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (251898989) 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, 1937620 + ... + 1937749.

It is an arithmetic number, because the mean of its divisors is an integer number (40691385).

Almost surely, 2^251898985 is an apocalyptic number.

It is an amenable number.

251898985 is a deficient number, since it is larger than the sum of its proper divisors (73632095).

251898985 is a wasteful number, since it uses less digits than its factorization.

251898985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3875387.

The product of its digits is 2073600, while the sum is 55.

The square root of 251898985 is about 15871.3258740409. The cubic root of 251898985 is about 631.5515507262.

The spelling of 251898985 in words is "two hundred fifty-one million, eight hundred ninety-eight thousand, nine hundred eighty-five".