249666520 has 16 divisors (see below), whose sum is σ = 561749760. Its totient is φ = 99866592.

The previous prime is 249666499. The next prime is 249666523. The reversal of 249666520 is 25666942.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 6241663 = 249666520 / (2 + 4 + 9 + 6 + 6 + 6 + 5 + 2 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249666523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3120792 + ... + 3120871.

It is an arithmetic number, because the mean of its divisors is an integer number (35109360).

Almost surely, 2^249666520 is an apocalyptic number.

249666520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

249666520 is an abundant number, since it is smaller than the sum of its proper divisors (312083240).

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

249666520 is a wasteful number, since it uses less digits than its factorization.

249666520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6241674 (or 6241670 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 249666520 is about 15800.8392182188. The cubic root of 249666520 is about 629.6802946611.

The spelling of 249666520 in words is "two hundred forty-nine million, six hundred sixty-six thousand, five hundred twenty".