21362819 has 4 divisors (see below), whose sum is σ = 21372096. Its totient is φ = 21353544.

The previous prime is 21362753. The next prime is 21362827. The reversal of 21362819 is 91826312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21362819 is a prime.

It is a super-2 number, since 2×21362819² = 912740071253522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21362839) 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, 1742 + ... + 6764.

It is an arithmetic number, because the mean of its divisors is an integer number (5343024).

Almost surely, 2^21362819 is an apocalyptic number.

21362819 is a deficient number, since it is larger than the sum of its proper divisors (9277).

21362819 is an equidigital number, since it uses as much as digits as its factorization.

21362819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9276.

The product of its digits is 5184, while the sum is 32.

The square root of 21362819 is about 4621.9929684066. The cubic root of 21362819 is about 277.4722272885.

The spelling of 21362819 in words is "twenty-one million, three hundred sixty-two thousand, eight hundred nineteen".