251878140 has 48 divisors (see below), whose sum is σ = 783622560. Its totient is φ = 67167360.

The previous prime is 251878127. The next prime is 251878153. The reversal of 251878140 is 41878152.

It is an interprime number because it is at equal distance from previous prime (251878127) and next prime (251878153).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 251878095 and 251878104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232681 + ... + 233760.

It is an arithmetic number, because the mean of its divisors is an integer number (16325470).

Almost surely, 2^251878140 is an apocalyptic number.

251878140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251878140 is an abundant number, since it is smaller than the sum of its proper divisors (531744420).

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

251878140 is a wasteful number, since it uses less digits than its factorization.

251878140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466459 (or 466451 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The square root of 251878140 is about 15870.6691730374. The cubic root of 251878140 is about 631.5341296487.

The spelling of 251878140 in words is "two hundred fifty-one million, eight hundred seventy-eight thousand, one hundred forty".