20842701921 has 16 divisors (see below), whose sum is σ = 31535059200. Its totient is φ = 13599492624.

The previous prime is 20842701907. The next prime is 20842701961. The reversal of 20842701921 is 12910724802.

20842701921 is a `hidden beast` number, since 208 + 427 + 0 + 1 + 9 + 21 = 666.

It is not a de Polignac number, because 20842701921 - 2²¹ = 20840604769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20842701961) 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, 8210986 + ... + 8213523.

It is an arithmetic number, because the mean of its divisors is an integer number (1970941200).

Almost surely, 2^20842701921 is an apocalyptic number.

It is an amenable number.

20842701921 is a deficient number, since it is larger than the sum of its proper divisors (10692357279).

20842701921 is a wasteful number, since it uses less digits than its factorization.

20842701921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16424565 (or 16424559 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 20842701921 in words is "twenty billion, eight hundred forty-two million, seven hundred one thousand, nine hundred twenty-one".