21366452 has 6 divisors (see below), whose sum is σ = 37391298. Its totient is φ = 10683224.

The previous prime is 21366407. The next prime is 21366463. The reversal of 21366452 is 25466312.

It can be written as a sum of positive squares in only one way, i.e., 20394256 + 972196 = 4516^2 + 986^2 .

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, 2670803 + ... + 2670810.

It is an arithmetic number, because the mean of its divisors is an integer number (6231883).

Almost surely, 2^21366452 is an apocalyptic number.

It is an amenable number.

21366452 is a deficient number, since it is larger than the sum of its proper divisors (16024846).

21366452 is a wasteful number, since it uses less digits than its factorization.

21366452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5341617 (or 5341615 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

The square root of 21366452 is about 4622.3859639801. The cubic root of 21366452 is about 277.4879555414.

The spelling of 21366452 in words is "twenty-one million, three hundred sixty-six thousand, four hundred fifty-two".