21099647918 has 8 divisors (see below), whose sum is σ = 31667050560. Its totient is φ = 10543964400.

The previous prime is 21099647857. The next prime is 21099647939. The reversal of 21099647918 is 81974699012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2925278 + ... + 2932481.

It is an arithmetic number, because the mean of its divisors is an integer number (3958381320).

Almost surely, 2^21099647918 is an apocalyptic number.

21099647918 is a deficient number, since it is larger than the sum of its proper divisors (10567402642).

21099647918 is a wasteful number, since it uses less digits than its factorization.

21099647918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5859562.

The product of its (nonzero) digits is 1959552, while the sum is 56.

The spelling of 21099647918 in words is "twenty-one billion, ninety-nine million, six hundred forty-seven thousand, nine hundred eighteen".