21166036 has 6 divisors (see below), whose sum is σ = 37040570. Its totient is φ = 10583016.

The previous prime is 21166009. The next prime is 21166051. The reversal of 21166036 is 63066112.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 2624400 = 4306^2 + 1620^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21166036.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2645751 + ... + 2645758.

Almost surely, 2^21166036 is an apocalyptic number.

It is an amenable number.

21166036 is a deficient number, since it is larger than the sum of its proper divisors (15874534).

21166036 is a wasteful number, since it uses less digits than its factorization.

21166036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5291513 (or 5291511 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21166036 is about 4600.6560401751. The cubic root of 21166036 is about 276.6176219897.

The spelling of 21166036 in words is "twenty-one million, one hundred sixty-six thousand, thirty-six".