20621442536501 has 4 divisors (see below), whose sum is σ = 20622347524512. Its totient is φ = 20620537548492.

The previous prime is 20621442536491. The next prime is 20621442536509. The reversal of 20621442536501 is 10563524412602.

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 20621442536501 - 2¹⁴ = 20621442520117 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 (20621442536509) 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, 452459825 + ... + 452505398.

It is an arithmetic number, because the mean of its divisors is an integer number (5155586881128).

Almost surely, 2^{20621442536501} is an apocalyptic number.

It is an amenable number.

20621442536501 is a deficient number, since it is larger than the sum of its proper divisors (904988011).

20621442536501 is an equidigital number, since it uses as much as digits as its factorization.

20621442536501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904988010.

The product of its (nonzero) digits is 345600, while the sum is 41.

The spelling of 20621442536501 in words is "twenty trillion, six hundred twenty-one billion, four hundred forty-two million, five hundred thirty-six thousand, five hundred one".