20336721891 has 8 divisors (see below), whose sum is σ = 27119893584. Its totient is φ = 13555682400.

The previous prime is 20336721883. The next prime is 20336721893. The reversal of 20336721891 is 19812763302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20336721891 - 2³ = 20336721883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20336721893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 510660 + ... + 549041.

It is an arithmetic number, because the mean of its divisors is an integer number (3389986698).

Almost surely, 2^20336721891 is an apocalyptic number.

20336721891 is a deficient number, since it is larger than the sum of its proper divisors (6783171693).

20336721891 is a wasteful number, since it uses less digits than its factorization.

20336721891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1066101.

The product of its (nonzero) digits is 108864, while the sum is 42.

The spelling of 20336721891 in words is "twenty billion, three hundred thirty-six million, seven hundred twenty-one thousand, eight hundred ninety-one".