21335990 has 32 divisors (see below), whose sum is σ = 42378336. Its totient is φ = 7683840.

The previous prime is 21335983. The next prime is 21335999. The reversal of 21335990 is 9953312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21335999) 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, 3329 + ... + 7331.

It is an arithmetic number, because the mean of its divisors is an integer number (1324323).

Almost surely, 2^21335990 is an apocalyptic number.

21335990 is a deficient number, since it is larger than the sum of its proper divisors (21042346).

21335990 is a wasteful number, since it uses less digits than its factorization.

21335990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4064.

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 21335990 is about 4619.0897371668. The cubic root of 21335990 is about 277.3560219486.

The spelling of 21335990 in words is "twenty-one million, three hundred thirty-five thousand, nine hundred ninety".