20406504361 has 4 divisors (see below), whose sum is σ = 20428710400. Its totient is φ = 20384298324.

The previous prime is 20406504343. The next prime is 20406504403. The reversal of 20406504361 is 16340560402.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16340560402 = 2 ⋅8170280201.

It is a cyclic number.

It is not a de Polignac number, because 20406504361 - 2⁵ = 20406504329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20406504331) 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, 11101641 + ... + 11103478.

It is an arithmetic number, because the mean of its divisors is an integer number (5107177600).

Almost surely, 2^20406504361 is an apocalyptic number.

It is an amenable number.

20406504361 is a deficient number, since it is larger than the sum of its proper divisors (22206039).

20406504361 is an equidigital number, since it uses as much as digits as its factorization.

20406504361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22206038.

The product of its (nonzero) digits is 17280, while the sum is 31.

The spelling of 20406504361 in words is "twenty billion, four hundred six million, five hundred four thousand, three hundred sixty-one".