21375735389 has 4 divisors (see below), whose sum is σ = 21668553756. Its totient is φ = 21082917024.

The previous prime is 21375735373. The next prime is 21375735419. The reversal of 21375735389 is 98353757312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18243094489 + 3132640900 = 135067^2 + 55970^2 .

It is a cyclic number.

It is not a de Polignac number, because 21375735389 - 2⁴ = 21375735373 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 21375735389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21375735089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146409074 + ... + 146409219.

It is an arithmetic number, because the mean of its divisors is an integer number (5417138439).

Almost surely, 2^21375735389 is an apocalyptic number.

It is an amenable number.

21375735389 is a deficient number, since it is larger than the sum of its proper divisors (292818367).

21375735389 is an equidigital number, since it uses as much as digits as its factorization.

21375735389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292818366.

The product of its digits is 4762800, while the sum is 53.

The spelling of 21375735389 in words is "twenty-one billion, three hundred seventy-five million, seven hundred thirty-five thousand, three hundred eighty-nine".