21459747 has 8 divisors (see below), whose sum is σ = 28728000. Its totient is φ = 14249000.

The previous prime is 21459743. The next prime is 21459751. The reversal of 21459747 is 74795412.

It is an interprime number because it is at equal distance from previous prime (21459743) and next prime (21459751).

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

It is a cyclic number.

It is not a de Polignac number, because 21459747 - 2² = 21459743 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21459743) 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 7 ways as a sum of consecutive naturals, for example, 13497 + ... + 15002.

It is an arithmetic number, because the mean of its divisors is an integer number (3591000).

Almost surely, 2^21459747 is an apocalyptic number.

21459747 is a deficient number, since it is larger than the sum of its proper divisors (7268253).

21459747 is a wasteful number, since it uses less digits than its factorization.

21459747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28753.

The product of its digits is 70560, while the sum is 39.

The square root of 21459747 is about 4632.4666215743. The cubic root of 21459747 is about 277.8912458688.

The spelling of 21459747 in words is "twenty-one million, four hundred fifty-nine thousand, seven hundred forty-seven".