21486981732621 has 4 divisors (see below), whose sum is σ = 28649308976832. Its totient is φ = 14324654488412.

The previous prime is 21486981732571. The next prime is 21486981732719. The reversal of 21486981732621 is 12623718968412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21486981732621 - 2⁹ = 21486981732109 is a prime.

It is a super-2 number, since 2×21486981732621² (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 (21486981732121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3581163622101 + ... + 3581163622106.

It is an arithmetic number, because the mean of its divisors is an integer number (7162327244208).

Almost surely, 2^{21486981732621} is an apocalyptic number.

It is an amenable number.

21486981732621 is a deficient number, since it is larger than the sum of its proper divisors (7162327244211).

21486981732621 is an equidigital number, since it uses as much as digits as its factorization.

21486981732621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7162327244210.

The product of its digits is 13934592, while the sum is 60.

The spelling of 21486981732621 in words is "twenty-one trillion, four hundred eighty-six billion, nine hundred eighty-one million, seven hundred thirty-two thousand, six hundred twenty-one".