21360990 has 32 divisors (see below), whose sum is σ = 58590720. Its totient is φ = 4882464.

The previous prime is 21360971. The next prime is 21361001. The reversal of 21360990 is 9906312.

It is a super-3 number, since 3×21360990³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

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, 50650 + ... + 51069.

It is an arithmetic number, because the mean of its divisors is an integer number (1830960).

Almost surely, 2^21360990 is an apocalyptic number.

21360990 is an abundant number, since it is smaller than the sum of its proper divisors (37229730).

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

21360990 is a wasteful number, since it uses less digits than its factorization.

21360990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101736.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 21360990 is about 4621.7951058003. The cubic root of 21360990 is about 277.4643083712.

The spelling of 21360990 in words is "twenty-one million, three hundred sixty thousand, nine hundred ninety".