21477437643621 has 8 divisors (see below), whose sum is σ = 28717706992320. Its totient is φ = 14277730028672.

The previous prime is 21477437643593. The next prime is 21477437643661. The reversal of 21477437643621 is 12634673477412.

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 21477437643621 - 2¹⁴ = 21477437627237 is a prime.

It is a super-2 number, since 2×21477437643621² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21477437643661) 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, 10140432201 + ... + 10140434318.

It is an arithmetic number, because the mean of its divisors is an integer number (3589713374040).

Almost surely, 2^{21477437643621} is an apocalyptic number.

It is an amenable number.

21477437643621 is a deficient number, since it is larger than the sum of its proper divisors (7240269348699).

21477437643621 is a wasteful number, since it uses less digits than its factorization.

21477437643621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20280866875.

The product of its digits is 28449792, while the sum is 57.

The spelling of 21477437643621 in words is "twenty-one trillion, four hundred seventy-seven billion, four hundred thirty-seven million, six hundred forty-three thousand, six hundred twenty-one".