251000730 has 48 divisors (see below), whose sum is σ = 653388840. Its totient is φ = 66852864.

The previous prime is 251000719. The next prime is 251000741. The reversal of 251000730 is 37000152.

It is an interprime number because it is at equal distance from previous prime (251000719) and next prime (251000741).

It can be written as a sum of positive squares in 4 ways, for example, as 90497169 + 160503561 = 9513^2 + 12669^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 133074 + ... + 134946.

Almost surely, 2^251000730 is an apocalyptic number.

251000730 is an abundant number, since it is smaller than the sum of its proper divisors (402388110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251000730 is a wasteful number, since it uses less digits than its factorization.

251000730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3375 (or 3372 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 18.

The square root of 251000730 is about 15843.0025563338. The cubic root of 251000730 is about 630.7999663976.

Adding to 251000730 its reverse (37000152), we get a palindrome (288000882).

The spelling of 251000730 in words is "two hundred fifty-one million, seven hundred thirty", and thus it is an aban number.