19997874 has 64 divisors (see below), whose sum is σ = 48746880. Its totient is φ = 6039360.

The previous prime is 19997869. The next prime is 19997893. The reversal of 19997874 is 47879991.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 19997874.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42589 + ... + 43055.

It is an arithmetic number, because the mean of its divisors is an integer number (761670).

Almost surely, 2^19997874 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19997874, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24373440).

19997874 is an abundant number, since it is smaller than the sum of its proper divisors (28749006).

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

19997874 is a wasteful number, since it uses less digits than its factorization.

19997874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552 (or 546 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The square root of 19997874 is about 4471.8982546565. The cubic root of 19997874 is about 271.4321432322.

The spelling of 19997874 in words is "nineteen million, nine hundred ninety-seven thousand, eight hundred seventy-four".