251680940 has 48 divisors (see below), whose sum is σ = 623529984. Its totient is φ = 83505600.

The previous prime is 251680939. The next prime is 251680943. The reversal of 251680940 is 49086152.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 251680940.

It is not an unprimeable number, because it can be changed into a prime (251680943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24656 + ... + 33335.

It is an arithmetic number, because the mean of its divisors is an integer number (12990208).

Almost surely, 2^251680940 is an apocalyptic number.

251680940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251680940 is an abundant number, since it is smaller than the sum of its proper divisors (371849044).

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

251680940 is a wasteful number, since it uses less digits than its factorization.

251680940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58038 (or 58036 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 251680940 is about 15864.4552380471. The cubic root of 251680940 is about 631.3692734135.

The spelling of 251680940 in words is "two hundred fifty-one million, six hundred eighty thousand, nine hundred forty".