21600819 has 12 divisors (see below), whose sum is σ = 31256992. Its totient is φ = 14374800.

The previous prime is 21600811. The next prime is 21600823. The reversal of 21600819 is 91800612.

It is not a de Polignac number, because 21600819 - 2³ = 21600811 is a prime.

It is a super-2 number, since 2×21600819² = 933190762941522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21600792 and 21600801.

It is not an unprimeable number, because it can be changed into a prime (21600811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4134 + ... + 7764.

Almost surely, 2^21600819 is an apocalyptic number.

21600819 is a deficient number, since it is larger than the sum of its proper divisors (9656173).

21600819 is a wasteful number, since it uses less digits than its factorization.

21600819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4298 (or 4295 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 21600819 is about 4647.6681249848. The cubic root of 21600819 is about 278.4988498438.

The spelling of 21600819 in words is "twenty-one million, six hundred thousand, eight hundred nineteen".