21074090 has 16 divisors (see below), whose sum is σ = 38959272. Its totient is φ = 8201664.

The previous prime is 21074089. The next prime is 21074093. The reversal of 21074090 is 9047012.

It can be written as a sum of positive squares in 4 ways, for example, as 16834609 + 4239481 = 4103^2 + 2059^2 .

It is not an unprimeable number, because it can be changed into a prime (21074093) 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, 28109 + ... + 28848.

Almost surely, 2^21074090 is an apocalyptic number.

21074090 is a deficient number, since it is larger than the sum of its proper divisors (17885182).

21074090 is a wasteful number, since it uses less digits than its factorization.

21074090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57001.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 21074090 is about 4590.6524590738. The cubic root of 21074090 is about 276.2164950527.

The spelling of 21074090 in words is "twenty-one million, seventy-four thousand, ninety".