21665102 has 4 divisors (see below), whose sum is σ = 32497656. Its totient is φ = 10832550.

The previous prime is 21665101. The next prime is 21665129. The reversal of 21665102 is 20156612.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21665101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5416274 + ... + 5416277.

It is an arithmetic number, because the mean of its divisors is an integer number (8124414).

Almost surely, 2^21665102 is an apocalyptic number.

21665102 is a deficient number, since it is larger than the sum of its proper divisors (10832554).

21665102 is a wasteful number, since it uses less digits than its factorization.

21665102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10832553.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21665102 is about 4654.5786060609. The cubic root of 21665102 is about 278.7748426451.

The spelling of 21665102 in words is "twenty-one million, six hundred sixty-five thousand, one hundred two".