21116604 has 12 divisors (see below), whose sum is σ = 49272104. Its totient is φ = 7038864.

The previous prime is 21116597. The next prime is 21116629. The reversal of 21116604 is 40661112.

It is a tau number, because it is divible by the number of its divisors (12).

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, 879847 + ... + 879870.

Almost surely, 2^21116604 is an apocalyptic number.

It is an amenable number.

21116604 is an abundant number, since it is smaller than the sum of its proper divisors (28155500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21116604 is a wasteful number, since it uses less digits than its factorization.

21116604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1759724 (or 1759722 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21116604 is about 4595.2806225518. The cubic root of 21116604 is about 276.4021128777.

Adding to 21116604 its reverse (40661112), we get a palindrome (61777716).

The spelling of 21116604 in words is "twenty-one million, one hundred sixteen thousand, six hundred four".