100531221 has 32 divisors (see below), whose sum is σ = 159667200. Its totient is φ = 55067520.

The previous prime is 100531199. The next prime is 100531231. The reversal of 100531221 is 122135001.

It is not a de Polignac number, because 100531221 - 2⁶ = 100531157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 100531221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100531231) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49810 + ... + 51788.

It is an arithmetic number, because the mean of its divisors is an integer number (4989600).

Almost surely, 2^100531221 is an apocalyptic number.

It is an amenable number.

100531221 is a deficient number, since it is larger than the sum of its proper divisors (59135979).

100531221 is a wasteful number, since it uses less digits than its factorization.

100531221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2089.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 100531221 is about 10026.5258689139. The cubic root of 100531221 is about 464.9793354211.

Adding to 100531221 its reverse (122135001), we get a palindrome (222666222).

The spelling of 100531221 in words is "one hundred million, five hundred thirty-one thousand, two hundred twenty-one".