21401620106623 has 8 divisors (see below), whose sum is σ = 21422048583456. Its totient is φ = 21381195801600.

The previous prime is 21401620106609. The next prime is 21401620106627. The reversal of 21401620106623 is 32660102610412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21401620106623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401620106627) 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, 9270678 + ... + 11346748.

It is an arithmetic number, because the mean of its divisors is an integer number (2677756072932).

Almost surely, 2^{21401620106623} is an apocalyptic number.

21401620106623 is a deficient number, since it is larger than the sum of its proper divisors (20428476833).

21401620106623 is a wasteful number, since it uses less digits than its factorization.

21401620106623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2085905.

The product of its (nonzero) digits is 20736, while the sum is 34.

The spelling of 21401620106623 in words is "twenty-one trillion, four hundred one billion, six hundred twenty million, one hundred six thousand, six hundred twenty-three".