21640822618 has 8 divisors (see below), whose sum is σ = 32526288000. Its totient is φ = 10798726620.

The previous prime is 21640822607. The next prime is 21640822631. The reversal of 21640822618 is 81622804612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10841098 + ... + 10843093.

It is an arithmetic number, because the mean of its divisors is an integer number (4065786000).

Almost surely, 2^21640822618 is an apocalyptic number.

21640822618 is a deficient number, since it is larger than the sum of its proper divisors (10885465382).

21640822618 is a wasteful number, since it uses less digits than its factorization.

21640822618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21684692.

The product of its (nonzero) digits is 73728, while the sum is 40.

The spelling of 21640822618 in words is "twenty-one billion, six hundred forty million, eight hundred twenty-two thousand, six hundred eighteen".