21369490 has 32 divisors (see below), whose sum is σ = 41368320. Its totient is φ = 7922304.

The previous prime is 21369473. The next prime is 21369499. The reversal of 21369490 is 9496312.

It is not an unprimeable number, because it can be changed into a prime (21369499) 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, 7734 + ... + 10126.

It is an arithmetic number, because the mean of its divisors is an integer number (1292760).

Almost surely, 2^21369490 is an apocalyptic number.

21369490 is a deficient number, since it is larger than the sum of its proper divisors (19998830).

21369490 is a wasteful number, since it uses less digits than its factorization.

21369490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2466.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 21369490 is about 4622.7145704661. The cubic root of 21369490 is about 277.5011065075.

The spelling of 21369490 in words is "twenty-one million, three hundred sixty-nine thousand, four hundred ninety".