21892099021 has 4 divisors (see below), whose sum is σ = 23576106652. Its totient is φ = 20208091392.

The previous prime is 21892098937. The next prime is 21892099057. The reversal of 21892099021 is 12099029812.

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 1141696521 + 20750402500 = 33789^2 + 144050^2 .

It is a cyclic number.

It is not a de Polignac number, because 21892099021 - 2²¹ = 21890001869 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 (21892091021) 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, 842003796 + ... + 842003821.

It is an arithmetic number, because the mean of its divisors is an integer number (5894026663).

Almost surely, 2^21892099021 is an apocalyptic number.

It is an amenable number.

21892099021 is a deficient number, since it is larger than the sum of its proper divisors (1684007631).

21892099021 is a wasteful number, since it uses less digits than its factorization.

21892099021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1684007630.

The product of its (nonzero) digits is 46656, while the sum is 43.

The spelling of 21892099021 in words is "twenty-one billion, eight hundred ninety-two million, ninety-nine thousand, twenty-one".