20455313440421 has 4 divisors (see below), whose sum is σ = 20536808713344. Its totient is φ = 20373818167500.

The previous prime is 20455313440391. The next prime is 20455313440439. The reversal of 20455313440421 is 12404431355402.

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 20455313440421 - 2²⁶ = 20455246331557 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 (20455313440021) 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, 40747636085 + ... + 40747636586.

It is an arithmetic number, because the mean of its divisors is an integer number (5134202178336).

Almost surely, 2^{20455313440421} is an apocalyptic number.

It is an amenable number.

20455313440421 is a deficient number, since it is larger than the sum of its proper divisors (81495272923).

20455313440421 is an equidigital number, since it uses as much as digits as its factorization.

20455313440421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81495272922.

The product of its (nonzero) digits is 230400, while the sum is 38.

Adding to 20455313440421 its reverse (12404431355402), we get a palindrome (32859744795823).

The spelling of 20455313440421 in words is "twenty trillion, four hundred fifty-five billion, three hundred thirteen million, four hundred forty thousand, four hundred twenty-one".