21839474 has 8 divisors (see below), whose sum is σ = 34483440. Its totient is φ = 10344996.

The previous prime is 21839473. The next prime is 21839479. The reversal of 21839474 is 47493812.

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

It is a Harshad number since it is a multiple of its sum of digits (38), and also a Moran number because the ratio is a prime number: 574723 = 21839474 / (2 + 1 + 8 + 3 + 9 + 4 + 7 + 4).

It is not an unprimeable number, because it can be changed into a prime (21839473) 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, 287324 + ... + 287399.

It is an arithmetic number, because the mean of its divisors is an integer number (4310430).

Almost surely, 2^21839474 is an apocalyptic number.

21839474 is a deficient number, since it is larger than the sum of its proper divisors (12643966).

21839474 is a wasteful number, since it uses less digits than its factorization.

21839474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574744.

The product of its digits is 48384, while the sum is 38.

The square root of 21839474 is about 4673.2723010756. The cubic root of 21839474 is about 279.5207533209.

The spelling of 21839474 in words is "twenty-one million, eight hundred thirty-nine thousand, four hundred seventy-four".