109961821 has 4 divisors (see below), whose sum is σ = 110047644. Its totient is φ = 109876000.

The previous prime is 109961809. The next prime is 109961861. The reversal of 109961821 is 128169901.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 236196 + 109725625 = 486^2 + 10475^2 .

It is a cyclic number.

It is not a de Polignac number, because 109961821 - 2⁷ = 109961693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109961861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40960 + ... + 43561.

It is an arithmetic number, because the mean of its divisors is an integer number (27511911).

Almost surely, 2^109961821 is an apocalyptic number.

It is an amenable number.

109961821 is a deficient number, since it is larger than the sum of its proper divisors (85823).

109961821 is an equidigital number, since it uses as much as digits as its factorization.

109961821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85822.

The product of its (nonzero) digits is 7776, while the sum is 37.

The square root of 109961821 is about 10486.2682113324. The cubic root of 109961821 is about 479.0865454678.

The spelling of 109961821 in words is "one hundred nine million, nine hundred sixty-one thousand, eight hundred twenty-one".