19972720 has 20 divisors (see below), whose sum is σ = 46436760. Its totient is φ = 7989056.

The previous prime is 19972709. The next prime is 19972723. The reversal of 19972720 is 2727991.

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 19972720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19972723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124750 + ... + 124909.

It is an arithmetic number, because the mean of its divisors is an integer number (2321838).

Almost surely, 2^19972720 is an apocalyptic number.

19972720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19972720 is an abundant number, since it is smaller than the sum of its proper divisors (26464040).

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

19972720 is a wasteful number, since it uses less digits than its factorization.

19972720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249672 (or 249666 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 19972720 is about 4469.0849175195. The cubic root of 19972720 is about 271.3182899830.

The spelling of 19972720 in words is "nineteen million, nine hundred seventy-two thousand, seven hundred twenty".