21386206618 has 32 divisors (see below), whose sum is σ = 40861756800. Its totient is φ = 8172347904.

The previous prime is 21386206609. The next prime is 21386206651. The reversal of 21386206618 is 81660268312.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2360163 + ... + 2369206.

It is an arithmetic number, because the mean of its divisors is an integer number (1276929900).

Almost surely, 2^21386206618 is an apocalyptic number.

21386206618 is a deficient number, since it is larger than the sum of its proper divisors (19475550182).

21386206618 is a wasteful number, since it uses less digits than its factorization.

21386206618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4729414.

The product of its (nonzero) digits is 165888, while the sum is 43.

The spelling of 21386206618 in words is "twenty-one billion, three hundred eighty-six million, two hundred six thousand, six hundred eighteen".