21720133707054 has 16 divisors (see below), whose sum is σ = 43442132803200. Its totient is φ = 7239733670840.

The previous prime is 21720133707043. The next prime is 21720133707061. The reversal of 21720133707054 is 45070733102712.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21720133706997 and 21720133707015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77573154 + ... + 77852645.

It is an arithmetic number, because the mean of its divisors is an integer number (2715133300200).

Almost surely, 2^{21720133707054} is an apocalyptic number.

21720133707054 is an abundant number, since it is smaller than the sum of its proper divisors (21721999096146).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21720133707054 is a wasteful number, since it uses less digits than its factorization.

21720133707054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155449095.

The product of its (nonzero) digits is 246960, while the sum is 42.

Adding to 21720133707054 its reverse (45070733102712), we get a palindrome (66790866809766).

The spelling of 21720133707054 in words is "twenty-one trillion, seven hundred twenty billion, one hundred thirty-three million, seven hundred seven thousand, fifty-four".