253387840 has 56 divisors (see below), whose sum is σ = 619716312. Its totient is φ = 98611200.

The previous prime is 253387817. The next prime is 253387847. The reversal of 253387840 is 48783352.

It can be written as a sum of positive squares in 4 ways, for example, as 37650496 + 215737344 = 6136^2 + 14688^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 253387793 and 253387802.

It is not an unprimeable number, because it can be changed into a prime (253387847) 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 7 ways as a sum of consecutive naturals, for example, 1140 + ... + 22540.

Almost surely, 2^253387840 is an apocalyptic number.

253387840 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 253387840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309858156).

253387840 is an abundant number, since it is smaller than the sum of its proper divisors (366328472).

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

253387840 is a wasteful number, since it uses less digits than its factorization.

253387840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21455 (or 21445 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The square root of 253387840 is about 15918.1606977691. The cubic root of 253387840 is about 632.7933741900.

The spelling of 253387840 in words is "two hundred fifty-three million, three hundred eighty-seven thousand, eight hundred forty".