21514664 has 8 divisors (see below), whose sum is σ = 40340010. Its totient is φ = 10757328.

The previous prime is 21514657. The next prime is 21514667. The reversal of 21514664 is 46641512.

It can be written as a sum of positive squares in only one way, i.e., 18062500 + 3452164 = 4250^2 + 1858^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21514667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1344659 + ... + 1344674.

Almost surely, 2^21514664 is an apocalyptic number.

It is an amenable number.

21514664 is a deficient number, since it is larger than the sum of its proper divisors (18825346).

21514664 is a wasteful number, since it uses less digits than its factorization.

21514664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2689339 (or 2689335 counting only the distinct ones).

The product of its digits is 5760, while the sum is 29.

The square root of 21514664 is about 4638.3902380028. The cubic root of 21514664 is about 278.1280916881.

The spelling of 21514664 in words is "twenty-one million, five hundred fourteen thousand, six hundred sixty-four".