20537637121 has 4 divisors (see below), whose sum is σ = 20660617152. Its totient is φ = 20414657092.

The previous prime is 20537637097. The next prime is 20537637143. The reversal of 20537637121 is 12173673502.

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 20537637121 - 2⁷ = 20537636993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20537637161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61489765 + ... + 61490098.

It is an arithmetic number, because the mean of its divisors is an integer number (5165154288).

Almost surely, 2^20537637121 is an apocalyptic number.

It is an amenable number.

20537637121 is a deficient number, since it is larger than the sum of its proper divisors (122980031).

20537637121 is a wasteful number, since it uses less digits than its factorization.

20537637121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122980030.

The product of its (nonzero) digits is 52920, while the sum is 37.

The spelling of 20537637121 in words is "twenty billion, five hundred thirty-seven million, six hundred thirty-seven thousand, one hundred twenty-one".