191920090 has 8 divisors (see below), whose sum is σ = 345456180. Its totient is φ = 76768032.

The previous prime is 191920087. The next prime is 191920103. The reversal of 191920090 is 90029191.

It can be written as a sum of positive squares in 2 ways, for example, as 185422689 + 6497401 = 13617^2 + 2549^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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, 9595995 + ... + 9596014.

Almost surely, 2^191920090 is an apocalyptic number.

191920090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

191920090 is a deficient number, since it is larger than the sum of its proper divisors (153536090).

191920090 is a wasteful number, since it uses less digits than its factorization.

191920090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19192016.

The product of its (nonzero) digits is 1458, while the sum is 31.

The square root of 191920090 is about 13853.5226567108. The cubic root of 191920090 is about 576.8197821814.

The spelling of 191920090 in words is "one hundred ninety-one million, nine hundred twenty thousand, ninety".