21297710 has 16 divisors (see below), whose sum is σ = 43812576. Its totient is φ = 7302048.

The previous prime is 21297691. The next prime is 21297733. The reversal of 21297710 is 1779212.

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 7 ways as a sum of consecutive naturals, for example, 152057 + ... + 152196.

It is an arithmetic number, because the mean of its divisors is an integer number (2738286).

Almost surely, 2^21297710 is an apocalyptic number.

21297710 is an abundant number, since it is smaller than the sum of its proper divisors (22514866).

21297710 is a wasteful number, since it uses less digits than its factorization.

21297710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304267.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21297710 is about 4614.9442033463. The cubic root of 21297710 is about 277.1900497349.

The spelling of 21297710 in words is "twenty-one million, two hundred ninety-seven thousand, seven hundred ten".