21138698 has 24 divisors (see below), whose sum is σ = 37791684. Its totient is φ = 8836800.

The previous prime is 21138619. The next prime is 21138713. The reversal of 21138698 is 89683112.

It can be written as a sum of positive squares in 2 ways, for example, as 20638849 + 499849 = 4543^2 + 707^2 .

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, 1388 + ... + 6648.

Almost surely, 2^21138698 is an apocalyptic number.

21138698 is a deficient number, since it is larger than the sum of its proper divisors (16652986).

21138698 is a wasteful number, since it uses less digits than its factorization.

21138698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5318 (or 5311 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

The square root of 21138698 is about 4597.6839821806. The cubic root of 21138698 is about 276.4984777997.

The spelling of 21138698 in words is "twenty-one million, one hundred thirty-eight thousand, six hundred ninety-eight".