21243698499 has 16 divisors (see below), whose sum is σ = 28458380160. Its totient is φ = 14095824000.

The previous prime is 21243698477. The next prime is 21243698503. The reversal of 21243698499 is 99489634212.

It is not a de Polignac number, because 21243698499 - 2⁸ = 21243698243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21243698459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1111744 + ... + 1130690.

It is an arithmetic number, because the mean of its divisors is an integer number (1778648760).

Almost surely, 2^21243698499 is an apocalyptic number.

21243698499 is a deficient number, since it is larger than the sum of its proper divisors (7214681661).

21243698499 is a wasteful number, since it uses less digits than its factorization.

21243698499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20690.

The product of its digits is 6718464, while the sum is 57.

The spelling of 21243698499 in words is "twenty-one billion, two hundred forty-three million, six hundred ninety-eight thousand, four hundred ninety-nine".