21893210 has 8 divisors (see below), whose sum is σ = 39407796. Its totient is φ = 8757280.

The previous prime is 21893203. The next prime is 21893219. The reversal of 21893210 is 1239812.

It can be written as a sum of positive squares in 2 ways, for example, as 21893041 + 169 = 4679^2 + 13^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21893210.

It is not an unprimeable number, because it can be changed into a prime (21893219) 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, 1094651 + ... + 1094670.

Almost surely, 2^21893210 is an apocalyptic number.

21893210 is a deficient number, since it is larger than the sum of its proper divisors (17514586).

21893210 is a wasteful number, since it uses less digits than its factorization.

21893210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2189328.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21893210 is about 4679.0180593796. The cubic root of 21893210 is about 279.7498190460.

The spelling of 21893210 in words is "twenty-one million, eight hundred ninety-three thousand, two hundred ten".