21324290 has 32 divisors (see below), whose sum is σ = 43772400. Its totient is φ = 7409664.

The previous prime is 21324287. The next prime is 21324301. The reversal of 21324290 is 9242312.

It can be written as a sum of positive squares in 8 ways, for example, as 3876961 + 17447329 = 1969^2 + 4177^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2615 + ... + 7034.

Almost surely, 2^21324290 is an apocalyptic number.

21324290 is an abundant number, since it is smaller than the sum of its proper divisors (22448110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21324290 is a wasteful number, since it uses less digits than its factorization.

21324290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9686.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21324290 is about 4617.8230801970. The cubic root of 21324290 is about 277.3053148444.

The spelling of 21324290 in words is "twenty-one million, three hundred twenty-four thousand, two hundred ninety".