21945195 has 16 divisors (see below), whose sum is σ = 39013920. Its totient is φ = 11704032.

The previous prime is 21945191. The next prime is 21945211. The reversal of 21945195 is 59154912.

It is not a de Polignac number, because 21945195 - 2² = 21945191 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21945191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81144 + ... + 81413.

It is an arithmetic number, because the mean of its divisors is an integer number (2438370).

Almost surely, 2^21945195 is an apocalyptic number.

21945195 is a deficient number, since it is larger than the sum of its proper divisors (17068725).

21945195 is a wasteful number, since it uses less digits than its factorization.

21945195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162571 (or 162565 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 21945195 is about 4684.5698842050. The cubic root of 21945195 is about 279.9710641867.

It can be divided in two parts, 21945 and 195, that multiplied together give a triangular number (4279275 = T₂₉₂₅).

The spelling of 21945195 in words is "twenty-one million, nine hundred forty-five thousand, one hundred ninety-five".