21391195 has 16 divisors (see below), whose sum is σ = 29937600. Its totient is φ = 14667072.

The previous prime is 21391193. The next prime is 21391211. The reversal of 21391195 is 59119312.

It is a happy number.

It is not a de Polignac number, because 21391195 - 2¹ = 21391193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21391193) 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, 4522 + ... + 7951.

It is an arithmetic number, because the mean of its divisors is an integer number (1871100).

Almost surely, 2^21391195 is an apocalyptic number.

21391195 is a deficient number, since it is larger than the sum of its proper divisors (8546405).

21391195 is an equidigital number, since it uses as much as digits as its factorization.

21391195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12499 (or 12485 counting only the distinct ones).

The product of its digits is 2430, while the sum is 31.

The square root of 21391195 is about 4625.0616212111. The cubic root of 21391195 is about 277.5950273798.

The spelling of 21391195 in words is "twenty-one million, three hundred ninety-one thousand, one hundred ninety-five".