21546481 has 16 divisors (see below), whose sum is σ = 24159168. Its totient is φ = 19051200.

The previous prime is 21546419. The next prime is 21546509. The reversal of 21546481 is 18464512.

It is a cyclic number.

It is not a de Polignac number, because 21546481 - 2⁷ = 21546353 is a prime.

It is a super-2 number, since 2×21546481² = 928501686966722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21546781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109275 + ... + 109471.

It is an arithmetic number, because the mean of its divisors is an integer number (1509948).

Almost surely, 2^21546481 is an apocalyptic number.

It is an amenable number.

21546481 is a deficient number, since it is larger than the sum of its proper divisors (2612687).

21546481 is a wasteful number, since it uses less digits than its factorization.

21546481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432.

The product of its digits is 7680, while the sum is 31.

The square root of 21546481 is about 4641.8187168393. The cubic root of 21546481 is about 278.2651275698.

The spelling of 21546481 in words is "twenty-one million, five hundred forty-six thousand, four hundred eighty-one".