20461564423 has 4 divisors (see below), whose sum is σ = 21167135640. Its totient is φ = 19755993208.

The previous prime is 20461564421. The next prime is 20461564471. The reversal of 20461564423 is 32446516402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32446516402 = 2 ⋅16223258201.

It is a cyclic number.

It is not a de Polignac number, because 20461564423 - 2¹ = 20461564421 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 (20461564421) 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, 352785565 + ... + 352785622.

It is an arithmetic number, because the mean of its divisors is an integer number (5291783910).

Almost surely, 2^20461564423 is an apocalyptic number.

20461564423 is a deficient number, since it is larger than the sum of its proper divisors (705571217).

20461564423 is an equidigital number, since it uses as much as digits as its factorization.

20461564423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705571216.

The product of its (nonzero) digits is 138240, while the sum is 37.

The spelling of 20461564423 in words is "twenty billion, four hundred sixty-one million, five hundred sixty-four thousand, four hundred twenty-three".