21493486 has 8 divisors (see below), whose sum is σ = 36846000. Its totient is φ = 9211488.

The previous prime is 21493481. The next prime is 21493487. The reversal of 21493486 is 68439412.

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

It is a super-3 number, since 3×21493486³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21493481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 767611 + ... + 767638.

It is an arithmetic number, because the mean of its divisors is an integer number (4605750).

Almost surely, 2^21493486 is an apocalyptic number.

21493486 is a deficient number, since it is larger than the sum of its proper divisors (15352514).

21493486 is a wasteful number, since it uses less digits than its factorization.

21493486 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535258.

The product of its digits is 41472, while the sum is 37.

The square root of 21493486 is about 4636.1067718507. The cubic root of 21493486 is about 278.0368030913.

The spelling of 21493486 in words is "twenty-one million, four hundred ninety-three thousand, four hundred eighty-six".