20538278298721 has 4 divisors (see below), whose sum is σ = 20674293386944. Its totient is φ = 20402263210500.

The previous prime is 20538278298701. The next prime is 20538278298757. The reversal of 20538278298721 is 12789287283502.

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 20538278298721 - 2⁵ = 20538278298689 is a prime.

It is a super-2 number, since 2×20538278298721² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20538278298701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68007543885 + ... + 68007544186.

It is an arithmetic number, because the mean of its divisors is an integer number (5168573346736).

Almost surely, 2^{20538278298721} is an apocalyptic number.

It is an amenable number.

20538278298721 is a deficient number, since it is larger than the sum of its proper divisors (136015088223).

20538278298721 is a wasteful number, since it uses less digits than its factorization.

20538278298721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136015088222.

The product of its (nonzero) digits is 54190080, while the sum is 64.

The spelling of 20538278298721 in words is "twenty trillion, five hundred thirty-eight billion, two hundred seventy-eight million, two hundred ninety-eight thousand, seven hundred twenty-one".