21486481 has 4 divisors (see below), whose sum is σ = 21641200. Its totient is φ = 21331764.

The previous prime is 21486467. The next prime is 21486523. The reversal of 21486481 is 18468412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21486481 - 2⁵ = 21486449 is a prime.

It is a super-2 number, since 2×21486481² = 923337731526722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21486461) 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, 77151 + ... + 77428.

It is an arithmetic number, because the mean of its divisors is an integer number (5410300).

Almost surely, 2^21486481 is an apocalyptic number.

It is an amenable number.

21486481 is a deficient number, since it is larger than the sum of its proper divisors (154719).

21486481 is a wasteful number, since it uses less digits than its factorization.

21486481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154718.

The product of its digits is 12288, while the sum is 34.

The square root of 21486481 is about 4635.3512272534. The cubic root of 21486481 is about 278.0065945678.

The spelling of 21486481 in words is "twenty-one million, four hundred eighty-six thousand, four hundred eighty-one".