21037519 has 4 divisors (see below), whose sum is σ = 21057696. Its totient is φ = 21017344.

The previous prime is 21037487. The next prime is 21037537. The reversal of 21037519 is 91573012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21037519 - 2⁵ = 21037487 is a prime.

It is a super-2 number, since 2×21037519² = 885154411350722, 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 (21037559) 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, 8434 + ... + 10639.

It is an arithmetic number, because the mean of its divisors is an integer number (5264424).

Almost surely, 2^21037519 is an apocalyptic number.

21037519 is a deficient number, since it is larger than the sum of its proper divisors (20177).

21037519 is a wasteful number, since it uses less digits than its factorization.

21037519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20176.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 21037519 is about 4586.6675266472. The cubic root of 21037519 is about 276.0566247679.

The spelling of 21037519 in words is "twenty-one million, thirty-seven thousand, five hundred nineteen".