21243195 has 32 divisors (see below), whose sum is σ = 38491200. Its totient is φ = 11112192.

The previous prime is 21243193. The next prime is 21243227. The reversal of 21243195 is 59134212.

It is not a de Polignac number, because 21243195 - 2¹ = 21243193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21243193) 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 31 ways as a sum of consecutive naturals, for example, 5671 + ... + 8639.

It is an arithmetic number, because the mean of its divisors is an integer number (1202850).

Almost surely, 2^21243195 is an apocalyptic number.

21243195 is a deficient number, since it is larger than the sum of its proper divisors (17248005).

21243195 is a wasteful number, since it uses less digits than its factorization.

21243195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3036 (or 3030 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 21243195 is about 4609.0340636624. The cubic root of 21243195 is about 276.9533431129.

The spelling of 21243195 in words is "twenty-one million, two hundred forty-three thousand, one hundred ninety-five".