21646104611540 has 48 divisors (see below), whose sum is σ = 46164692234640. Its totient is φ = 8524047467520.

The previous prime is 21646104611501. The next prime is 21646104611557. The reversal of 21646104611540 is 4511640164612.

It can be written as a sum of positive squares in 8 ways, for example, as 3012015786256 + 18634088825284 = 1735516^2 + 4316722^2 .

It is a congruent number.

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, 12912635 + ... + 14492354.

It is an arithmetic number, because the mean of its divisors is an integer number (961764421555).

Almost surely, 2^{21646104611540} is an apocalyptic number.

21646104611540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21646104611540 is an abundant number, since it is smaller than the sum of its proper divisors (24518587623100).

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

21646104611540 is a wasteful number, since it uses less digits than its factorization.

21646104611540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27405612 (or 27405610 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 41.

The spelling of 21646104611540 in words is "twenty-one trillion, six hundred forty-six billion, one hundred four million, six hundred eleven thousand, five hundred forty".