251778268 has 18 divisors (see below), whose sum is σ = 512549016. Its totient is φ = 107904888.

The previous prime is 251778257. The next prime is 251778277. The reversal of 251778268 is 862877152.

251778268 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 642096 + ... + 642487.

Almost surely, 2^251778268 is an apocalyptic number.

251778268 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

251778268 is an abundant number, since it is smaller than the sum of its proper divisors (260770748).

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

251778268 is a wasteful number, since it uses less digits than its factorization.

251778268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1284601 (or 1284592 counting only the distinct ones).

The product of its digits is 376320, while the sum is 46.

The square root of 251778268 is about 15867.5224279029. The cubic root of 251778268 is about 631.4506489164.

The spelling of 251778268 in words is "two hundred fifty-one million, seven hundred seventy-eight thousand, two hundred sixty-eight".