109891221 has 16 divisors (see below), whose sum is σ = 164163648. Its totient is φ = 64800000.

The previous prime is 109891219. The next prime is 109891259. The reversal of 109891221 is 122198901.

It is not a de Polignac number, because 109891221 - 2¹ = 109891219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109891261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43780 + ... + 46221.

It is an arithmetic number, because the mean of its divisors is an integer number (10260228).

Almost surely, 2^109891221 is an apocalyptic number.

109891221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

109891221 is a deficient number, since it is larger than the sum of its proper divisors (54272427).

109891221 is a wasteful number, since it uses less digits than its factorization.

109891221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90052.

The product of its (nonzero) digits is 2592, while the sum is 33.

The square root of 109891221 is about 10482.9013636493. The cubic root of 109891221 is about 478.9839924451.

It can be divided in two parts, 10989 and 1221, that multiplied together give a square (13417569 = 3663²).

The spelling of 109891221 in words is "one hundred nine million, eight hundred ninety-one thousand, two hundred twenty-one".