21716830 has 16 divisors (see below), whose sum is σ = 40790304. Its totient is φ = 8308960.

The previous prime is 21716809. The next prime is 21716831. The reversal of 21716830 is 3861712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716831) 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, 46981 + ... + 47440.

It is an arithmetic number, because the mean of its divisors is an integer number (2549394).

Almost surely, 2^21716830 is an apocalyptic number.

21716830 is a deficient number, since it is larger than the sum of its proper divisors (19073474).

21716830 is a wasteful number, since it uses less digits than its factorization.

21716830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94451.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21716830 is about 4660.1319723802. The cubic root of 21716830 is about 278.9965356301.

The spelling of 21716830 in words is "twenty-one million, seven hundred sixteen thousand, eight hundred thirty".