19721272 has 8 divisors (see below), whose sum is σ = 36977400. Its totient is φ = 9860632.

The previous prime is 19721269. The next prime is 19721279. The reversal of 19721272 is 27212791.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19721279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1232572 + ... + 1232587.

It is an arithmetic number, because the mean of its divisors is an integer number (4622175).

Almost surely, 2^19721272 is an apocalyptic number.

It is an amenable number.

19721272 is a deficient number, since it is larger than the sum of its proper divisors (17256128).

19721272 is a wasteful number, since it uses less digits than its factorization.

19721272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2465165 (or 2465161 counting only the distinct ones).

The product of its digits is 3528, while the sum is 31.

The square root of 19721272 is about 4440.8638799225. The cubic root of 19721272 is about 270.1748844132.

The spelling of 19721272 in words is "nineteen million, seven hundred twenty-one thousand, two hundred seventy-two".