253997640 has 256 divisors, whose sum is σ = 927360000. Its totient is φ = 61461504.

The previous prime is 253997621. The next prime is 253997641. The reversal of 253997640 is 46799352.

It is a happy number.

253997640 is a `hidden beast` number, since 2 + 539 + 9 + 76 + 40 = 666.

It is a super-2 number, since 2×253997640² = 129029602251139200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (253997641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1109046 + ... + 1109274.

It is an arithmetic number, because the mean of its divisors is an integer number (3622500).

Almost surely, 2^253997640 is an apocalyptic number.

253997640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 253997640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (463680000).

253997640 is an abundant number, since it is smaller than the sum of its proper divisors (673362360).

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

253997640 is a wasteful number, since it uses less digits than its factorization.

253997640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341 (or 331 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 45.

The square root of 253997640 is about 15937.3034105522. The cubic root of 253997640 is about 633.3005917207.

The spelling of 253997640 in words is "two hundred fifty-three million, nine hundred ninety-seven thousand, six hundred forty".