190011981 has 8 divisors (see below), whose sum is σ = 254165184. Its totient is φ = 126266720.

The previous prime is 190011979. The next prime is 190012021. The reversal of 190011981 is 189110091.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 190011981 - 2¹ = 190011979 is a prime.

It is a super-2 number, since 2×190011981² = 72209105847088722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (190011181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100896 + ... + 102761.

It is an arithmetic number, because the mean of its divisors is an integer number (31770648).

Almost surely, 2^190011981 is an apocalyptic number.

It is an amenable number.

190011981 is a deficient number, since it is larger than the sum of its proper divisors (64153203).

190011981 is a wasteful number, since it uses less digits than its factorization.

190011981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203971.

The product of its (nonzero) digits is 648, while the sum is 30.

The square root of 190011981 is about 13784.4833417869. The cubic root of 190011981 is about 574.9017914187.

The spelling of 190011981 in words is "one hundred ninety million, eleven thousand, nine hundred eighty-one".