21480705 has 24 divisors (see below), whose sum is σ = 37343592. Its totient is φ = 11422464.

The previous prime is 21480691. The next prime is 21480713. The reversal of 21480705 is 50708412.

It can be written as a sum of positive squares in 4 ways, for example, as 2322576 + 19158129 = 1524^2 + 4377^2 .

It is not a de Polignac number, because 21480705 - 2⁷ = 21480577 is a prime.

It is a super-2 number, since 2×21480705² = 922841374594050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24637 + ... + 25493.

It is an arithmetic number, because the mean of its divisors is an integer number (1555983).

Almost surely, 2^21480705 is an apocalyptic number.

It is an amenable number.

21480705 is a deficient number, since it is larger than the sum of its proper divisors (15862887).

21480705 is a wasteful number, since it uses less digits than its factorization.

21480705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1425 (or 1422 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 21480705 is about 4634.7281473674. The cubic root of 21480705 is about 277.9816810730.

The spelling of 21480705 in words is "twenty-one million, four hundred eighty thousand, seven hundred five".