21708070 has 32 divisors (see below), whose sum is σ = 41827680. Its totient is φ = 8087040.

The previous prime is 21708059. The next prime is 21708097. The reversal of 21708070 is 7080712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 10654 + ... + 12526.

It is an arithmetic number, because the mean of its divisors is an integer number (1307115).

Almost surely, 2^21708070 is an apocalyptic number.

21708070 is a deficient number, since it is larger than the sum of its proper divisors (20119610).

21708070 is a wasteful number, since it uses less digits than its factorization.

21708070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1960.

The product of its (nonzero) digits is 784, while the sum is 25.

The square root of 21708070 is about 4659.1919900343. The cubic root of 21708070 is about 278.9590172885.

Adding to 21708070 its reverse (7080712), we get a palindrome (28788782).

The spelling of 21708070 in words is "twenty-one million, seven hundred eight thousand, seventy".