21280486 has 8 divisors (see below), whose sum is σ = 32024304. Its totient is φ = 10605720.

The previous prime is 21280459. The next prime is 21280487. The reversal of 21280486 is 68408212.

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 (21280487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16485 + ... + 17728.

It is an arithmetic number, because the mean of its divisors is an integer number (4003038).

Almost surely, 2^21280486 is an apocalyptic number.

21280486 is a deficient number, since it is larger than the sum of its proper divisors (10743818).

21280486 is a wasteful number, since it uses less digits than its factorization.

21280486 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34526.

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 21280486 is about 4613.0777144982. The cubic root of 21280486 is about 277.1153060335.

Adding to 21280486 its reverse (68408212), we get a palindrome (89688698).

The spelling of 21280486 in words is "twenty-one million, two hundred eighty thousand, four hundred eighty-six".