21009098 has 16 divisors (see below), whose sum is σ = 36188640. Its totient is φ = 9046800.

The previous prime is 21009091. The next prime is 21009139. The reversal of 21009098 is 89090012.

It is a self number, because there is not a number n which added to its sum of digits gives 21009098.

It is not an unprimeable number, because it can be changed into a prime (21009091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24713 + ... + 25548.

It is an arithmetic number, because the mean of its divisors is an integer number (2261790).

Almost surely, 2^21009098 is an apocalyptic number.

21009098 is a deficient number, since it is larger than the sum of its proper divisors (15179542).

21009098 is a wasteful number, since it uses less digits than its factorization.

21009098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50293.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 21009098 is about 4583.5682606458. The cubic root of 21009098 is about 275.9322542543.

The spelling of 21009098 in words is "twenty-one million, nine thousand, ninety-eight".