20423521426621 has 4 divisors (see below), whose sum is σ = 20423665201212. Its totient is φ = 20423377652032.

The previous prime is 20423521426577. The next prime is 20423521426681. The reversal of 20423521426621 is 12662412532402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10215886212900 + 10207635213721 = 3196230^2 + 3194939^2 .

It is a cyclic number.

It is not a de Polignac number, because 20423521426621 - 2¹⁹ = 20423520902333 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 (20423521426681) 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, 71674006 + ... + 71958391.

It is an arithmetic number, because the mean of its divisors is an integer number (5105916300303).

Almost surely, 2^{20423521426621} is an apocalyptic number.

It is an amenable number.

20423521426621 is a deficient number, since it is larger than the sum of its proper divisors (143774591).

20423521426621 is a wasteful number, since it uses less digits than its factorization.

20423521426621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143774590.

The product of its (nonzero) digits is 276480, while the sum is 40.

The spelling of 20423521426621 in words is "twenty trillion, four hundred twenty-three billion, five hundred twenty-one million, four hundred twenty-six thousand, six hundred twenty-one".