21069396 has 30 divisors (see below), whose sum is σ = 55080410. Its totient is φ = 7023024.

The previous prime is 21069383. The next prime is 21069421. The reversal of 21069396 is 69396012.

It can be written as a sum of positive squares in only one way, i.e., 21068100 + 1296 = 4590^2 + 36^2 .

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 21069396.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 32191 + ... + 32838.

Almost surely, 2^21069396 is an apocalyptic number.

It is an amenable number.

21069396 is an abundant number, since it is smaller than the sum of its proper divisors (34011014).

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

21069396 is a wasteful number, since it uses less digits than its factorization.

21069396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65045 (or 65034 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 21069396 is about 4590.1411742995. The cubic root of 21069396 is about 276.1959855629.

The spelling of 21069396 in words is "twenty-one million, sixty-nine thousand, three hundred ninety-six".