21069738 has 12 divisors (see below), whose sum is σ = 45651138. Its totient is φ = 7023240.

The previous prime is 21069733. The next prime is 21069751. The reversal of 21069738 is 83796012.

It can be written as a sum of positive squares in only one way, i.e., 19474569 + 1595169 = 4413^2 + 1263^2 .

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (21069733) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 585253 + ... + 585288.

Almost surely, 2^21069738 is an apocalyptic number.

21069738 is an abundant number, since it is smaller than the sum of its proper divisors (24581400).

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

21069738 is a wasteful number, since it uses less digits than its factorization.

21069738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170549 (or 1170546 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21069738 is about 4590.1784279045. The cubic root of 21069738 is about 276.1974799660.

The spelling of 21069738 in words is "twenty-one million, sixty-nine thousand, seven hundred thirty-eight".