21298090 has 16 divisors (see below), whose sum is σ = 41821920. Its totient is φ = 7744720.

The previous prime is 21298073. The next prime is 21298091. The reversal of 21298090 is 9089212.

It is not an unprimeable number, because it can be changed into a prime (21298091) 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, 96700 + ... + 96919.

It is an arithmetic number, because the mean of its divisors is an integer number (2613870).

Almost surely, 2^21298090 is an apocalyptic number.

21298090 is a deficient number, since it is larger than the sum of its proper divisors (20523830).

21298090 is a wasteful number, since it uses less digits than its factorization.

21298090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193637.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 21298090 is about 4614.9853737580. The cubic root of 21298090 is about 277.1916982939.

The spelling of 21298090 in words is "twenty-one million, two hundred ninety-eight thousand, ninety".