21884690 has 16 divisors (see below), whose sum is σ = 39553920. Its totient is φ = 8718000.

The previous prime is 21884689. The next prime is 21884699. The reversal of 21884690 is 9648812.

It is a super-2 number, since 2×21884690² = 957879312792200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21884699) 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, 1850 + ... + 6869.

It is an arithmetic number, because the mean of its divisors is an integer number (2472120).

Almost surely, 2^21884690 is an apocalyptic number.

21884690 is a deficient number, since it is larger than the sum of its proper divisors (17669230).

21884690 is a wasteful number, since it uses less digits than its factorization.

21884690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8977.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 21884690 is about 4678.1075233474. The cubic root of 21884690 is about 279.7135250275.

The spelling of 21884690 in words is "twenty-one million, eight hundred eighty-four thousand, six hundred ninety".