21011730618 has 32 divisors (see below), whose sum is σ = 44502483456. Its totient is φ = 6590870528.

The previous prime is 21011730611. The next prime is 21011730683. The reversal of 21011730618 is 81603711012.

It is not an unprimeable number, because it can be changed into a prime (21011730611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 859330 + ... + 883442.

It is an arithmetic number, because the mean of its divisors is an integer number (1390702608).

Almost surely, 2^21011730618 is an apocalyptic number.

21011730618 is an abundant number, since it is smaller than the sum of its proper divisors (23490752838).

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

21011730618 is a wasteful number, since it uses less digits than its factorization.

21011730618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32678.

The product of its (nonzero) digits is 2016, while the sum is 30.

The spelling of 21011730618 in words is "twenty-one billion, eleven million, seven hundred thirty thousand, six hundred eighteen".