21533398 has 8 divisors (see below), whose sum is σ = 32782392. Its totient is φ = 10605936.

The previous prime is 21533363. The next prime is 21533431. The reversal of 21533398 is 89333512.

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

It is a congruent number.

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, 80215 + ... + 80482.

It is an arithmetic number, because the mean of its divisors is an integer number (4097799).

Almost surely, 2^21533398 is an apocalyptic number.

21533398 is a deficient number, since it is larger than the sum of its proper divisors (11248994).

21533398 is a wasteful number, since it uses less digits than its factorization.

21533398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160766.

The product of its digits is 19440, while the sum is 34.

The square root of 21533398 is about 4640.4092491934. The cubic root of 21533398 is about 278.2087954050.

The spelling of 21533398 in words is "twenty-one million, five hundred thirty-three thousand, three hundred ninety-eight".