21531195 has 48 divisors (see below), whose sum is σ = 44141760. Its totient is φ = 9499392.

The previous prime is 21531193. The next prime is 21531233. The reversal of 21531195 is 59113512.

It is not a de Polignac number, because 21531195 - 2¹ = 21531193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21531193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7957 + ... + 10313.

It is an arithmetic number, because the mean of its divisors is an integer number (919620).

Almost surely, 2^21531195 is an apocalyptic number.

21531195 is an abundant number, since it is smaller than the sum of its proper divisors (22610565).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21531195 is a wasteful number, since it uses less digits than its factorization.

21531195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2404 (or 2401 counting only the distinct ones).

The product of its digits is 1350, while the sum is 27.

The square root of 21531195 is about 4640.1718718168. The cubic root of 21531195 is about 278.1993075870.

The spelling of 21531195 in words is "twenty-one million, five hundred thirty-one thousand, one hundred ninety-five".