190739921 has 4 divisors (see below), whose sum is σ = 195895092. Its totient is φ = 185584752.

The previous prime is 190739911. The next prime is 190739929. The reversal of 190739921 is 129937091.

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 93993025 + 96746896 = 9695^2 + 9836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-190739921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (190739929) 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 3 ways as a sum of consecutive naturals, for example, 2577530 + ... + 2577603.

It is an arithmetic number, because the mean of its divisors is an integer number (48973773).

Almost surely, 2^190739921 is an apocalyptic number.

It is an amenable number.

190739921 is a deficient number, since it is larger than the sum of its proper divisors (5155171).

190739921 is an equidigital number, since it uses as much as digits as its factorization.

190739921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5155170.

The product of its (nonzero) digits is 30618, while the sum is 41.

The square root of 190739921 is about 13810.8624278138. The cubic root of 190739921 is about 575.6350096129.

The spelling of 190739921 in words is "one hundred ninety million, seven hundred thirty-nine thousand, nine hundred twenty-one".