21428519 has 8 divisors (see below), whose sum is σ = 24614400. Its totient is φ = 18273816.

The previous prime is 21428509. The next prime is 21428531. The reversal of 21428519 is 91582412.

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

It is a cyclic number.

It is not a de Polignac number, because 21428519 - 2⁴ = 21428503 is a prime.

It is a super-2 number, since 2×21428519² = 918362853066722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21428509) 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, 6299 + ... + 9084.

It is an arithmetic number, because the mean of its divisors is an integer number (3076800).

Almost surely, 2^21428519 is an apocalyptic number.

21428519 is a deficient number, since it is larger than the sum of its proper divisors (3185881).

21428519 is a wasteful number, since it uses less digits than its factorization.

21428519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15589.

The product of its digits is 5760, while the sum is 32.

The square root of 21428519 is about 4629.0948359263. The cubic root of 21428519 is about 277.7563856178.

The spelling of 21428519 in words is "twenty-one million, four hundred twenty-eight thousand, five hundred nineteen".