21297634 has 16 divisors (see below), whose sum is σ = 34237728. Its totient is φ = 9900352.

The previous prime is 21297631. The next prime is 21297641. The reversal of 21297634 is 43679212.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a self number, because there is not a number n which added to its sum of digits gives 21297634.

It is not an unprimeable number, because it can be changed into a prime (21297631) 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, 952 + ... + 6595.

It is an arithmetic number, because the mean of its divisors is an integer number (2139858).

Almost surely, 2^21297634 is an apocalyptic number.

21297634 is a deficient number, since it is larger than the sum of its proper divisors (12940094).

21297634 is a wasteful number, since it uses less digits than its factorization.

21297634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7649.

The product of its digits is 18144, while the sum is 34.

The square root of 21297634 is about 4614.9359692199. The cubic root of 21297634 is about 277.1897200208.

The spelling of 21297634 in words is "twenty-one million, two hundred ninety-seven thousand, six hundred thirty-four".