21428798 has 8 divisors (see below), whose sum is σ = 32175792. Its totient is φ = 10703536.

The previous prime is 21428791. The next prime is 21428807. The reversal of 21428798 is 89782412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21428791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2690 + ... + 7077.

It is an arithmetic number, because the mean of its divisors is an integer number (4021974).

Almost surely, 2^21428798 is an apocalyptic number.

21428798 is a deficient number, since it is larger than the sum of its proper divisors (10746994).

21428798 is a wasteful number, since it uses less digits than its factorization.

21428798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10866.

The product of its digits is 64512, while the sum is 41.

The square root of 21428798 is about 4629.1249713094. The cubic root of 21428798 is about 277.7575910782.

The spelling of 21428798 in words is "twenty-one million, four hundred twenty-eight thousand, seven hundred ninety-eight".