21026297 has 8 divisors (see below), whose sum is σ = 22413312. Its totient is φ = 19656000.

The previous prime is 21026287. The next prime is 21026303. The reversal of 21026297 is 79262012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21026297 - 2¹⁰ = 21025273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21026237) 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, 1529 + ... + 6662.

It is an arithmetic number, because the mean of its divisors is an integer number (2801664).

Almost surely, 2^21026297 is an apocalyptic number.

It is an amenable number.

21026297 is a deficient number, since it is larger than the sum of its proper divisors (1387015).

21026297 is a wasteful number, since it uses less digits than its factorization.

21026297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8359.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 21026297 is about 4585.4440352053. Note that the first 3 decimals coincide. The cubic root of 21026297 is about 276.0075306004.

The spelling of 21026297 in words is "twenty-one million, twenty-six thousand, two hundred ninety-seven".