21428698 has 8 divisors (see below), whose sum is σ = 33011892. Its totient is φ = 10424736.

The previous prime is 21428689. The next prime is 21428699. The reversal of 21428698 is 89682412.

It can be written as a sum of positive squares in 2 ways, for example, as 21040569 + 388129 = 4587^2 + 623^2 .

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 21428698.

It is not an unprimeable number, because it can be changed into a prime (21428699) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144715 + ... + 144862.

Almost surely, 2^21428698 is an apocalyptic number.

21428698 is a deficient number, since it is larger than the sum of its proper divisors (11583194).

21428698 is a wasteful number, since it uses less digits than its factorization.

21428698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289616.

The product of its digits is 55296, while the sum is 40.

The square root of 21428698 is about 4629.1141701194. The cubic root of 21428698 is about 277.7571590147.

The spelling of 21428698 in words is "twenty-one million, four hundred twenty-eight thousand, six hundred ninety-eight".