109819921 has 2 divisors, whose sum is σ = 109819922. Its totient is φ = 109819920.

The previous prime is 109819909. The next prime is 109819933. The reversal of 109819921 is 129918901.

It is a balanced prime because it is at equal distance from previous prime (109819909) and next prime (109819933).

It can be written as a sum of positive squares in only one way, i.e., 109411600 + 408321 = 10460^2 + 639^2 .

It is a cyclic number.

It is not a de Polignac number, because 109819921 - 2⁷ = 109819793 is a prime.

It is a super-4 number, since 4×109819921⁴ (a number of 33 digits) contains 4444 as substring.

It is the 10480-th Hogben number.

It is not a weakly prime, because it can be changed into another prime (109819951) by changing a digit.

It is a nontrivial repunit in base 10479.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54909960 + 54909961.

It is an arithmetic number, because the mean of its divisors is an integer number (54909961).

Almost surely, 2^109819921 is an apocalyptic number.

It is an amenable number.

109819921 is a deficient number, since it is larger than the sum of its proper divisors (1).

109819921 is an equidigital number, since it uses as much as digits as its factorization.

109819921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 109819921 is about 10479.5000357841. The cubic root of 109819921 is about 478.8803780189.

It can be divided in two parts, 10981 and 9921, that added together give a palindrome (20902).

The spelling of 109819921 in words is "one hundred nine million, eight hundred nineteen thousand, nine hundred twenty-one".