20199972 has 48 divisors (see below), whose sum is σ = 52408832. Its totient is φ = 6013440.

The previous prime is 20199953. The next prime is 20199973. The reversal of 20199972 is 27999102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 20199972.

It is not an unprimeable number, because it can be changed into a prime (20199973) 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, 2748 + ... + 6924.

Almost surely, 2^20199972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20199972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26204416).

20199972 is an abundant number, since it is smaller than the sum of its proper divisors (32208860).

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

20199972 is a wasteful number, since it uses less digits than its factorization.

20199972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4228 (or 4226 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 20199972 is about 4494.4378958887. The cubic root of 20199972 is about 272.3434423215.

The spelling of 20199972 in words is "twenty million, one hundred ninety-nine thousand, nine hundred seventy-two".