21486688171621 has 8 divisors (see below), whose sum is σ = 21513997614560. Its totient is φ = 21459384069552.

The previous prime is 21486688171589. The next prime is 21486688171631. The reversal of 21486688171621 is 12617188668412.

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

It is a cyclic number.

It is not a de Polignac number, because 21486688171621 - 2⁵ = 21486688171589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21486688171621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21486688171631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6747091 + ... + 9407263.

It is an arithmetic number, because the mean of its divisors is an integer number (2689249701820).

Almost surely, 2^{21486688171621} is an apocalyptic number.

It is an amenable number.

21486688171621 is a deficient number, since it is larger than the sum of its proper divisors (27309442939).

21486688171621 is an equidigital number, since it uses as much as digits as its factorization.

21486688171621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2670435.

The product of its digits is 12386304, while the sum is 61.

The spelling of 21486688171621 in words is "twenty-one trillion, four hundred eighty-six billion, six hundred eighty-eight million, one hundred seventy-one thousand, six hundred twenty-one".