21445459 has 16 divisors (see below), whose sum is σ = 25993216. Its totient is φ = 17301600.

The previous prime is 21445451. The next prime is 21445469. The reversal of 21445459 is 95454412.

It is a cyclic number.

It is not a de Polignac number, because 21445459 - 2³ = 21445451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21445451) 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, 6694 + ... + 9364.

It is an arithmetic number, because the mean of its divisors is an integer number (1624576).

Almost surely, 2^21445459 is an apocalyptic number.

21445459 is a deficient number, since it is larger than the sum of its proper divisors (4547757).

21445459 is a wasteful number, since it uses less digits than its factorization.

21445459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2746.

The product of its digits is 28800, while the sum is 34.

The square root of 21445459 is about 4630.9242058146. The cubic root of 21445459 is about 277.8295584121.

It can be divided in two parts, 21445 and 459, that added together give a square (21904 = 148²).

The spelling of 21445459 in words is "twenty-one million, four hundred forty-five thousand, four hundred fifty-nine".