20191974 has 64 divisors (see below), whose sum is σ = 46448640. Its totient is φ = 5796000.

The previous prime is 20191931. The next prime is 20191987. The reversal of 20191974 is 47919102.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

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, 145197 + ... + 145335.

It is an arithmetic number, because the mean of its divisors is an integer number (725760).

Almost surely, 2^20191974 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20191974, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23224320).

20191974 is an abundant number, since it is smaller than the sum of its proper divisors (26256666).

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

20191974 is a wasteful number, since it uses less digits than its factorization.

20191974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 20191974 is about 4493.5480413589. The cubic root of 20191974 is about 272.3074935853.

It can be divided in two parts, 2019 and 1974, that added together give a palindrome (3993).

The spelling of 20191974 in words is "twenty million, one hundred ninety-one thousand, nine hundred seventy-four".