21998267858 has 24 divisors (see below), whose sum is σ = 38444170752. Its totient is φ = 9413230344.

The previous prime is 21998267827. The next prime is 21998267981. The reversal of 21998267858 is 85876289912.

It is a junction number, because it is equal to n+sod(n) for n = 21998267794 and 21998267803.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 110066 + ... + 236877.

It is an arithmetic number, because the mean of its divisors is an integer number (1601840448).

Almost surely, 2^21998267858 is an apocalyptic number.

21998267858 is a deficient number, since it is larger than the sum of its proper divisors (16445902894).

21998267858 is a wasteful number, since it uses less digits than its factorization.

21998267858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347606 (or 347599 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 65.

The spelling of 21998267858 in words is "twenty-one billion, nine hundred ninety-eight million, two hundred sixty-seven thousand, eight hundred fifty-eight".