21018898 has 16 divisors (see below), whose sum is σ = 32175360. Its totient is φ = 10296000.

The previous prime is 21018869. The next prime is 21018929. The reversal of 21018898 is 89881012.

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, 23418 + ... + 24298.

It is an arithmetic number, because the mean of its divisors is an integer number (2010960).

Almost surely, 2^21018898 is an apocalyptic number.

21018898 is a deficient number, since it is larger than the sum of its proper divisors (11156462).

21018898 is a wasteful number, since it uses less digits than its factorization.

21018898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 21018898 is about 4584.6371721217. The cubic root of 21018898 is about 275.9751517923.

The spelling of 21018898 in words is "twenty-one million, eighteen thousand, eight hundred ninety-eight".