19974921 has 8 divisors (see below), whose sum is σ = 26772000. Its totient is φ = 13247232.

The previous prime is 19974907. The next prime is 19974923. The reversal of 19974921 is 12947991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19974921 - 2⁷ = 19974793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19974923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16671 + ... + 17828.

It is an arithmetic number, because the mean of its divisors is an integer number (3346500).

Almost surely, 2^19974921 is an apocalyptic number.

It is an amenable number.

19974921 is a deficient number, since it is larger than the sum of its proper divisors (6797079).

19974921 is a wasteful number, since it uses less digits than its factorization.

19974921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34695.

The product of its digits is 40824, while the sum is 42.

The square root of 19974921 is about 4469.3311580146. The cubic root of 19974921 is about 271.3282560705.

The spelling of 19974921 in words is "nineteen million, nine hundred seventy-four thousand, nine hundred twenty-one".