109206721 has 16 divisors (see below), whose sum is σ = 124966800. Its totient is φ = 94687488.

The previous prime is 109206701. The next prime is 109206761. The reversal of 109206721 is 127602901.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2890000 + 106316721 = 1700^2 + 10311^2 .

It is a cyclic number.

It is not a de Polignac number, because 109206721 - 2⁷ = 109206593 is a prime.

It is a super-2 number, since 2×109206721² = 23852215823143682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 109206721.

It is not an unprimeable number, because it can be changed into a prime (109206701) 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 15 ways as a sum of consecutive naturals, for example, 10035 + ... + 17863.

It is an arithmetic number, because the mean of its divisors is an integer number (7810425).

Almost surely, 2^109206721 is an apocalyptic number.

It is an amenable number.

109206721 is a deficient number, since it is larger than the sum of its proper divisors (15760079).

109206721 is a wasteful number, since it uses less digits than its factorization.

109206721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7908.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 109206721 is about 10450.2019597709. The cubic root of 109206721 is about 477.9874079770.

The spelling of 109206721 in words is "one hundred nine million, two hundred six thousand, seven hundred twenty-one".