19997772 has 12 divisors (see below), whose sum is σ = 46661496. Its totient is φ = 6665920.

The previous prime is 19997743. The next prime is 19997779. The reversal of 19997772 is 27779991.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (19997779) 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, 833229 + ... + 833252.

It is an arithmetic number, because the mean of its divisors is an integer number (3888458).

Almost surely, 2^19997772 is an apocalyptic number.

19997772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

19997772 is an abundant number, since it is smaller than the sum of its proper divisors (26663724).

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

19997772 is a wasteful number, since it uses less digits than its factorization.

19997772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666488 (or 1666486 counting only the distinct ones).

The product of its digits is 500094, while the sum is 51.

The square root of 19997772 is about 4471.8868500891. The cubic root of 19997772 is about 271.4316817478.

The spelling of 19997772 in words is "nineteen million, nine hundred ninety-seven thousand, seven hundred seventy-two".