21710090 has 16 divisors (see below), whose sum is σ = 39185640. Its totient is φ = 8660160.

The previous prime is 21710057. The next prime is 21710111. The reversal of 21710090 is 9001712.

It can be written as a sum of positive squares in 4 ways, for example, as 12752041 + 8958049 = 3571^2 + 2993^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1100 + ... + 6680.

Almost surely, 2^21710090 is an apocalyptic number.

21710090 is a deficient number, since it is larger than the sum of its proper divisors (17475550).

21710090 is a wasteful number, since it uses less digits than its factorization.

21710090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5977.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 21710090 is about 4659.4087607764. The cubic root of 21710090 is about 278.9676696735.

The spelling of 21710090 in words is "twenty-one million, seven hundred ten thousand, ninety".