268821021 has 32 divisors (see below), whose sum is σ = 422560000. Its totient is φ = 148801536.

The previous prime is 268821013. The next prime is 268821023. The reversal of 268821021 is 120128862.

It is not a de Polignac number, because 268821021 - 2³ = 268821013 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 268821021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (268821023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 214605 + ... + 215853.

It is an arithmetic number, because the mean of its divisors is an integer number (13205000).

Almost surely, 2^268821021 is an apocalyptic number.

268821021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

268821021 is a deficient number, since it is larger than the sum of its proper divisors (153738979).

268821021 is a wasteful number, since it uses less digits than its factorization.

268821021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573.

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 268821021 is about 16395.7622878596. The cubic root of 268821021 is about 645.3882813262.

Adding to 268821021 its reverse (120128862), we get a palindrome (388949883).

The spelling of 268821021 in words is "two hundred sixty-eight million, eight hundred twenty-one thousand, twenty-one".