21499774 has 16 divisors (see below), whose sum is σ = 33083136. Its totient is φ = 10474200.

The previous prime is 21499763. The next prime is 21499783. The reversal of 21499774 is 47799412.

It is a self number, because there is not a number n which added to its sum of digits gives 21499774.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30769 + ... + 31459.

It is an arithmetic number, because the mean of its divisors is an integer number (2067696).

Almost surely, 2^21499774 is an apocalyptic number.

21499774 is a deficient number, since it is larger than the sum of its proper divisors (11583362).

21499774 is a wasteful number, since it uses less digits than its factorization.

21499774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071.

The product of its digits is 127008, while the sum is 43.

The square root of 21499774 is about 4636.7848774771. The cubic root of 21499774 is about 278.0639140178.

The spelling of 21499774 in words is "twenty-one million, four hundred ninety-nine thousand, seven hundred seventy-four".