20710721121 has 16 divisors (see below), whose sum is σ = 29242814400. Its totient is φ = 12993118208.

The previous prime is 20710721117. The next prime is 20710721131. The reversal of 20710721121 is 12112701702.

It is a cyclic number.

It is not a de Polignac number, because 20710721121 - 2² = 20710721117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20710721091 and 20710721100.

It is not an unprimeable number, because it can be changed into a prime (20710721131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 394465 + ... + 443873.

It is an arithmetic number, because the mean of its divisors is an integer number (1827675900).

Almost surely, 2^20710721121 is an apocalyptic number.

It is an amenable number.

20710721121 is a deficient number, since it is larger than the sum of its proper divisors (8532093279).

20710721121 is a wasteful number, since it uses less digits than its factorization.

20710721121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57648.

The product of its (nonzero) digits is 392, while the sum is 24.

The spelling of 20710721121 in words is "twenty billion, seven hundred ten million, seven hundred twenty-one thousand, one hundred twenty-one".