21306195 has 12 divisors (see below), whose sum is σ = 36930816. Its totient is φ = 11363280.

The previous prime is 21306193. The next prime is 21306209. The reversal of 21306195 is 59160312.

It is not a de Polignac number, because 21306195 - 2¹ = 21306193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21306193) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 236691 + ... + 236780.

It is an arithmetic number, because the mean of its divisors is an integer number (3077568).

Almost surely, 2^21306195 is an apocalyptic number.

21306195 is a deficient number, since it is larger than the sum of its proper divisors (15624621).

21306195 is a wasteful number, since it uses less digits than its factorization.

21306195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473482 (or 473479 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 21306195 is about 4615.8634078577. The cubic root of 21306195 is about 277.2268556529.

The spelling of 21306195 in words is "twenty-one million, three hundred six thousand, one hundred ninety-five".