521268618 has 64 divisors (see below), whose sum is σ = 1165127040. Its totient is φ = 154441728.

The previous prime is 521268613. The next prime is 521268647. The reversal of 521268618 is 816862125.

It is a super-2 number, since 2×521268618² = 543441944223259848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (521268613) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 243778 + ... + 245906.

It is an arithmetic number, because the mean of its divisors is an integer number (18205110).

Almost surely, 2^521268618 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521268618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (582563520).

521268618 is an abundant number, since it is smaller than the sum of its proper divisors (643858422).

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

521268618 is a wasteful number, since it uses less digits than its factorization.

521268618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2263.

The product of its digits is 46080, while the sum is 39.

The square root of 521268618 is about 22831.3078469018. The cubic root of 521268618 is about 804.7985648789.

The spelling of 521268618 in words is "five hundred twenty-one million, two hundred sixty-eight thousand, six hundred eighteen".