21093490 has 32 divisors (see below), whose sum is σ = 41648256. Its totient is φ = 7628160.

The previous prime is 21093487. The next prime is 21093491. The reversal of 21093490 is 9439012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21093491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25219 + ... + 26041.

It is an arithmetic number, because the mean of its divisors is an integer number (1301508).

Almost surely, 2^21093490 is an apocalyptic number.

21093490 is a deficient number, since it is larger than the sum of its proper divisors (20554766).

21093490 is a wasteful number, since it uses less digits than its factorization.

21093490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1074.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 21093490 is about 4592.7649624164. The cubic root of 21093490 is about 276.3012271659.

The spelling of 21093490 in words is "twenty-one million, ninety-three thousand, four hundred ninety".