21830216 has 8 divisors (see below), whose sum is σ = 40931670. Its totient is φ = 10915104.

The previous prime is 21830213. The next prime is 21830219. The reversal of 21830216 is 61203812.

It is an interprime number because it is at equal distance from previous prime (21830213) and next prime (21830219).

It can be written as a sum of positive squares in only one way, i.e., 21808900 + 21316 = 4670^2 + 146^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21830191 and 21830200.

It is not an unprimeable number, because it can be changed into a prime (21830213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1364381 + ... + 1364396.

Almost surely, 2^21830216 is an apocalyptic number.

It is an amenable number.

21830216 is a deficient number, since it is larger than the sum of its proper divisors (19101454).

21830216 is a wasteful number, since it uses less digits than its factorization.

21830216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2728783 (or 2728779 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21830216 is about 4672.2816695914. The cubic root of 21830216 is about 279.4812504024.

The spelling of 21830216 in words is "twenty-one million, eight hundred thirty thousand, two hundred sixteen".