100821255 has 32 divisors (see below), whose sum is σ = 170976960. Its totient is φ = 50641920.

The previous prime is 100821233. The next prime is 100821289. The reversal of 100821255 is 552128001.

It is not a de Polignac number, because 100821255 - 2⁵ = 100821223 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15009 + ... + 20661.

It is an arithmetic number, because the mean of its divisors is an integer number (5343030).

Almost surely, 2^100821255 is an apocalyptic number.

100821255 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

100821255 is a deficient number, since it is larger than the sum of its proper divisors (70155705).

100821255 is a wasteful number, since it uses less digits than its factorization.

100821255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5731.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 100821255 is about 10040.9787869510. The cubic root of 100821255 is about 465.4260634189.

Adding to 100821255 its reverse (552128001), we get a palindrome (652949256).

The spelling of 100821255 in words is "one hundred million, eight hundred twenty-one thousand, two hundred fifty-five".