21519938 has 8 divisors (see below), whose sum is σ = 35214480. Its totient is φ = 9781780.

The previous prime is 21519929. The next prime is 21520003. The reversal of 21519938 is 83991512.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 489068 + ... + 489111.

It is an arithmetic number, because the mean of its divisors is an integer number (4401810).

Almost surely, 2^21519938 is an apocalyptic number.

21519938 is a deficient number, since it is larger than the sum of its proper divisors (13694542).

21519938 is a wasteful number, since it uses less digits than its factorization.

21519938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978192.

The product of its digits is 19440, while the sum is 38.

The square root of 21519938 is about 4638.9587193680. The cubic root of 21519938 is about 278.1508161535.

The spelling of 21519938 in words is "twenty-one million, five hundred nineteen thousand, nine hundred thirty-eight".