21899309573 has 4 divisors (see below), whose sum is σ = 22100220780. Its totient is φ = 21698398368.

The previous prime is 21899309569. The next prime is 21899309591. The reversal of 21899309573 is 37590399812.

It is a happy number.

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 8962976929 + 12936332644 = 94673^2 + 113738^2 .

It is a cyclic number.

It is not a de Polignac number, because 21899309573 - 2² = 21899309569 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21899309563) 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, 100455440 + ... + 100455657.

It is an arithmetic number, because the mean of its divisors is an integer number (5525055195).

Almost surely, 2^21899309573 is an apocalyptic number.

It is an amenable number.

21899309573 is a deficient number, since it is larger than the sum of its proper divisors (200911207).

21899309573 is a wasteful number, since it uses less digits than its factorization.

21899309573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200911206.

The product of its (nonzero) digits is 3674160, while the sum is 56.

The spelling of 21899309573 in words is "twenty-one billion, eight hundred ninety-nine million, three hundred nine thousand, five hundred seventy-three".