21480709 has 8 divisors (see below), whose sum is σ = 21732480. Its totient is φ = 21230736.

The previous prime is 21480691. The next prime is 21480713. The reversal of 21480709 is 90708412.

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 21480709 - 2⁷ = 21480581 is a prime.

It is a super-2 number, since 2×21480709² = 922841718285362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21480749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48712 + ... + 49150.

It is an arithmetic number, because the mean of its divisors is an integer number (2716560).

Almost surely, 2^21480709 is an apocalyptic number.

It is an amenable number.

21480709 is a deficient number, since it is larger than the sum of its proper divisors (251771).

21480709 is a wasteful number, since it uses less digits than its factorization.

21480709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21480709 is about 4634.7285788922. The cubic root of 21480709 is about 277.9816983276.

The spelling of 21480709 in words is "twenty-one million, four hundred eighty thousand, seven hundred nine".