21299371918 has 16 divisors (see below), whose sum is σ = 34861728384. Its totient is φ = 9679251960.

The previous prime is 21299371909. The next prime is 21299371939. The reversal of 21299371918 is 81917399212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16680 + ... + 207067.

It is an arithmetic number, because the mean of its divisors is an integer number (2178858024).

Almost surely, 2^21299371918 is an apocalyptic number.

21299371918 is a deficient number, since it is larger than the sum of its proper divisors (13562356466).

21299371918 is a wasteful number, since it uses less digits than its factorization.

21299371918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228087.

The product of its digits is 489888, while the sum is 52.

The spelling of 21299371918 in words is "twenty-one billion, two hundred ninety-nine million, three hundred seventy-one thousand, nine hundred eighteen".