21494736 has 30 divisors (see below), whose sum is σ = 60155810. Its totient is φ = 7164864.

The previous prime is 21494729. The next prime is 21494779. The reversal of 21494736 is 63749412.

It can be written as a sum of positive squares in only one way, i.e., 18870336 + 2624400 = 4344^2 + 1620^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21494736.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 74491 + ... + 74778.

Almost surely, 2^21494736 is an apocalyptic number.

It is an amenable number.

21494736 is an abundant number, since it is smaller than the sum of its proper divisors (38661074).

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

21494736 is a wasteful number, since it uses less digits than its factorization.

21494736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149283 (or 149274 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21494736 is about 4636.2415812811. The cubic root of 21494736 is about 278.0421929300.

The spelling of 21494736 in words is "twenty-one million, four hundred ninety-four thousand, seven hundred thirty-six".