21240718075 has 12 divisors (see below), whose sum is σ = 26610024280. Its totient is φ = 16817391360.

The previous prime is 21240718049. The next prime is 21240718091. The reversal of 21240718075 is 57081704212.

It is a de Polignac number, because none of the positive numbers 2^k-21240718075 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4377105 + ... + 4381954.

Almost surely, 2^21240718075 is an apocalyptic number.

21240718075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21240718075 is a deficient number, since it is larger than the sum of its proper divisors (5369306205).

21240718075 is an equidigital number, since it uses as much as digits as its factorization.

21240718075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8759166 (or 8759161 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 37.

The spelling of 21240718075 in words is "twenty-one billion, two hundred forty million, seven hundred eighteen thousand, seventy-five".