21301266 has 32 divisors (see below), whose sum is σ = 50807808. Its totient is φ = 5821200.

The previous prime is 21301253. The next prime is 21301277. The reversal of 21301266 is 66210312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10060 + ... + 11991.

It is an arithmetic number, because the mean of its divisors is an integer number (1587744).

Almost surely, 2^21301266 is an apocalyptic number.

21301266 is an abundant number, since it is smaller than the sum of its proper divisors (29506542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21301266 is a wasteful number, since it uses less digits than its factorization.

21301266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22086.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21301266 is about 4615.3294573627. The cubic root of 21301266 is about 277.2054760094.

Adding to 21301266 its reverse (66210312), we get a palindrome (87511578).

The spelling of 21301266 in words is "twenty-one million, three hundred one thousand, two hundred sixty-six".