21609325019 has 4 divisors (see below), whose sum is σ = 21645766296. Its totient is φ = 21572883744.

The previous prime is 21609324911. The next prime is 21609325021. The reversal of 21609325019 is 91052390612.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21609325019 is a prime.

It is a super-2 number, since 2×21609325019² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21609325099) 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, 18219749 + ... + 18220934.

It is an arithmetic number, because the mean of its divisors is an integer number (5411441574).

Almost surely, 2^21609325019 is an apocalyptic number.

21609325019 is a deficient number, since it is larger than the sum of its proper divisors (36441277).

21609325019 is an equidigital number, since it uses as much as digits as its factorization.

21609325019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36441276.

The product of its (nonzero) digits is 29160, while the sum is 38.

The spelling of 21609325019 in words is "twenty-one billion, six hundred nine million, three hundred twenty-five thousand, nineteen".