21297158 has 16 divisors (see below), whose sum is σ = 33915024. Its totient is φ = 9995520.

The previous prime is 21297151. The next prime is 21297161. The reversal of 21297158 is 85179212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21297151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18866 + ... + 19962.

It is an arithmetic number, because the mean of its divisors is an integer number (2119689).

Almost surely, 2^21297158 is an apocalyptic number.

21297158 is a deficient number, since it is larger than the sum of its proper divisors (12617866).

21297158 is a wasteful number, since it uses less digits than its factorization.

21297158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687.

The product of its digits is 10080, while the sum is 35.

The square root of 21297158 is about 4614.8843972520. The cubic root of 21297158 is about 277.1876549512.

The spelling of 21297158 in words is "twenty-one million, two hundred ninety-seven thousand, one hundred fifty-eight".