19721946954 has 16 divisors (see below), whose sum is σ = 39557569248. Its totient is φ = 6555036432.

The previous prime is 19721946913. The next prime is 19721946983. The reversal of 19721946954 is 45964912791.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 19721946894 and 19721946903.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4734217 + ... + 4738380.

It is an arithmetic number, because the mean of its divisors is an integer number (2472348078).

Almost surely, 2^19721946954 is an apocalyptic number.

19721946954 is an abundant number, since it is smaller than the sum of its proper divisors (19835622294).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19721946954 is a wasteful number, since it uses less digits than its factorization.

19721946954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9472949.

The product of its digits is 4898880, while the sum is 57.

The spelling of 19721946954 in words is "nineteen billion, seven hundred twenty-one million, nine hundred forty-six thousand, nine hundred fifty-four".