21873639890 has 16 divisors (see below), whose sum is σ = 39846921408. Its totient is φ = 8644040496.

The previous prime is 21873639707. The next prime is 21873639899. The reversal of 21873639890 is 9893637812.

It is a super-2 number, since 2×21873639890² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21873639899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13176062 + ... + 13177721.

It is an arithmetic number, because the mean of its divisors is an integer number (2490432588).

Almost surely, 2^21873639890 is an apocalyptic number.

21873639890 is a deficient number, since it is larger than the sum of its proper divisors (17973281518).

21873639890 is a wasteful number, since it uses less digits than its factorization.

21873639890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26353873.

The product of its (nonzero) digits is 3919104, while the sum is 56.

The spelling of 21873639890 in words is "twenty-one billion, eight hundred seventy-three million, six hundred thirty-nine thousand, eight hundred ninety".