20404302240021 has 12 divisors (see below), whose sum is σ = 31647489188832. Its totient is φ = 11659601279928.

The previous prime is 20404302240017. The next prime is 20404302240029. The reversal of 20404302240021 is 12004220340402.

It is not a de Polignac number, because 20404302240021 - 2² = 20404302240017 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20404302239973 and 20404302240000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20404302240029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69402388425 + ... + 69402388718.

It is an arithmetic number, because the mean of its divisors is an integer number (2637290765736).

Almost surely, 2^{20404302240021} is an apocalyptic number.

20404302240021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20404302240021 is a deficient number, since it is larger than the sum of its proper divisors (11243186948811).

20404302240021 is a wasteful number, since it uses less digits than its factorization.

20404302240021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138804777160 (or 138804777153 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 20404302240021 its reverse (12004220340402), we get a palindrome (32408522580423).

The spelling of 20404302240021 in words is "twenty trillion, four hundred four billion, three hundred two million, two hundred forty thousand, twenty-one".