21669364 has 12 divisors (see below), whose sum is σ = 38348100. Its totient is φ = 10712768.

The previous prime is 21669353. The next prime is 21669371. The reversal of 21669364 is 46396612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 9972964 + 11696400 = 3158^2 + 3420^2 .

It is a super-2 number, since 2×21669364² = 939122672328992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30079 + ... + 30790.

It is an arithmetic number, because the mean of its divisors is an integer number (3195675).

Almost surely, 2^21669364 is an apocalyptic number.

It is an amenable number.

21669364 is a deficient number, since it is larger than the sum of its proper divisors (16678736).

21669364 is a wasteful number, since it uses less digits than its factorization.

21669364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60962 (or 60960 counting only the distinct ones).

The product of its digits is 46656, while the sum is 37.

The square root of 21669364 is about 4655.0364123173. The cubic root of 21669364 is about 278.7931218186.

The spelling of 21669364 in words is "twenty-one million, six hundred sixty-nine thousand, three hundred sixty-four".