21660195 has 32 divisors (see below), whose sum is σ = 35633664. Its totient is φ = 11232000.

The previous prime is 21660173. The next prime is 21660211. The reversal of 21660195 is 59106612.

It is not a de Polignac number, because 21660195 - 2⁶ = 21660131 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 143370 + ... + 143520.

It is an arithmetic number, because the mean of its divisors is an integer number (1113552).

Almost surely, 2^21660195 is an apocalyptic number.

21660195 is a deficient number, since it is larger than the sum of its proper divisors (13973469).

21660195 is a wasteful number, since it uses less digits than its factorization.

21660195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 21660195 is about 4654.0514608242. The cubic root of 21660195 is about 278.7537941798.

The spelling of 21660195 in words is "twenty-one million, six hundred sixty thousand, one hundred ninety-five".