21831898 has 8 divisors (see below), whose sum is σ = 35724960. Its totient is φ = 9923580.

The previous prime is 21831881. The next prime is 21831911. The reversal of 21831898 is 89813812.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21831898.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496158 + ... + 496201.

It is an arithmetic number, because the mean of its divisors is an integer number (4465620).

Almost surely, 2^21831898 is an apocalyptic number.

21831898 is a deficient number, since it is larger than the sum of its proper divisors (13893062).

21831898 is a wasteful number, since it uses less digits than its factorization.

21831898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992372.

The product of its digits is 27648, while the sum is 40.

The square root of 21831898 is about 4672.4616638342. The cubic root of 21831898 is about 279.4884281507.

The spelling of 21831898 in words is "twenty-one million, eight hundred thirty-one thousand, eight hundred ninety-eight".