21873639899 has 2 divisors, whose sum is σ = 21873639900. Its totient is φ = 21873639898.

The previous prime is 21873639707. The next prime is 21873639913. The reversal of 21873639899 is 99893637812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21873639899 - 2³² = 17578672603 is a prime.

It is a super-3 number, since 3×21873639899³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (21873639199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936819949 + 10936819950.

It is an arithmetic number, because the mean of its divisors is an integer number (10936819950).

Almost surely, 2^21873639899 is an apocalyptic number.

21873639899 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873639899 is an equidigital number, since it uses as much as digits as its factorization.

21873639899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35271936, while the sum is 65.

The spelling of 21873639899 in words is "twenty-one billion, eight hundred seventy-three million, six hundred thirty-nine thousand, eight hundred ninety-nine".