251440016 has 10 divisors (see below), whose sum is σ = 487165062. Its totient is φ = 125720000.

The previous prime is 251440009. The next prime is 251440027. The reversal of 251440016 is 610044152.

It can be written as a sum of positive squares in only one way, i.e., 233967616 + 17472400 = 15296^2 + 4180^2 .

It is a junction number, because it is equal to n+sod(n) for n = 251439973 and 251440000.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7857485 + ... + 7857516.

Almost surely, 2^251440016 is an apocalyptic number.

It is an amenable number.

251440016 is a deficient number, since it is larger than the sum of its proper divisors (235725046).

251440016 is a wasteful number, since it uses less digits than its factorization.

251440016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15715009 (or 15715003 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 251440016 is about 15856.8602188453. The cubic root of 251440016 is about 631.1677476596.

Adding to 251440016 its reverse (610044152), we get a palindrome (861484168).

The spelling of 251440016 in words is "two hundred fifty-one million, four hundred forty thousand, sixteen".