190765721 has 12 divisors (see below), whose sum is σ = 203588892. Its totient is φ = 178710528.

The previous prime is 190765693. The next prime is 190765739. The reversal of 190765721 is 127567091.

It can be written as a sum of positive squares in 6 ways, for example, as 1290496 + 189475225 = 1136^2 + 13765^2 .

It is not a de Polignac number, because 190765721 - 2¹⁴ = 190749337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (190765781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65921 + ... + 68753.

It is an arithmetic number, because the mean of its divisors is an integer number (16965741).

Almost surely, 2^190765721 is an apocalyptic number.

It is an amenable number.

190765721 is a deficient number, since it is larger than the sum of its proper divisors (12823171).

190765721 is a wasteful number, since it uses less digits than its factorization.

190765721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3100 (or 3083 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 38.

The square root of 190765721 is about 13811.7964436202. The cubic root of 190765721 is about 575.6609624279.

The spelling of 190765721 in words is "one hundred ninety million, seven hundred sixty-five thousand, seven hundred twenty-one".