21423537728075 has 18 divisors (see below), whose sum is σ = 30902360136876. Its totient is φ = 14690425869840.

The previous prime is 21423537728051. The next prime is 21423537728077. The reversal of 21423537728075 is 57082773532412.

It is not a de Polignac number, because 21423537728075 - 2¹⁶ = 21423537662539 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21423537728075.

It is not an unprimeable number, because it can be changed into a prime (21423537728077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8744299889 + ... + 8744302338.

It is an arithmetic number, because the mean of its divisors is an integer number (1716797785382).

Almost surely, 2^{21423537728075} is an apocalyptic number.

21423537728075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21423537728075 is a deficient number, since it is larger than the sum of its proper divisors (9478822408801).

21423537728075 is a wasteful number, since it uses less digits than its factorization.

21423537728075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17488602251 (or 17488602239 counting only the distinct ones).

The product of its (nonzero) digits is 19756800, while the sum is 56.

The spelling of 21423537728075 in words is "twenty-one trillion, four hundred twenty-three billion, five hundred thirty-seven million, seven hundred twenty-eight thousand, seventy-five".