21107764 has 12 divisors (see below), whose sum is σ = 37044000. Its totient is φ = 10523768.

The previous prime is 21107753. The next prime is 21107771. The reversal of 21107764 is 46770112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5914 + ... + 8785.

It is an arithmetic number, because the mean of its divisors is an integer number (3087000).

Almost surely, 2^21107764 is an apocalyptic number.

It is an amenable number.

21107764 is a deficient number, since it is larger than the sum of its proper divisors (15936236).

21107764 is a wasteful number, since it uses less digits than its factorization.

21107764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15062 (or 15060 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21107764 is about 4594.3186654824. The cubic root of 21107764 is about 276.3635376138.

Adding to 21107764 its reverse (46770112), we get a palindrome (67877876).

The spelling of 21107764 in words is "twenty-one million, one hundred seven thousand, seven hundred sixty-four".