190811681 has 4 divisors (see below), whose sum is σ = 194871552. Its totient is φ = 186751812.

The previous prime is 190811671. The next prime is 190811693. The reversal of 190811681 is 186118091.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-190811681 is a prime.

It is a super-2 number, since 2×190811681² = 72818195212091522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (190811671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2029865 + ... + 2029958.

It is an arithmetic number, because the mean of its divisors is an integer number (48717888).

Almost surely, 2^190811681 is an apocalyptic number.

It is an amenable number.

190811681 is a deficient number, since it is larger than the sum of its proper divisors (4059871).

190811681 is an equidigital number, since it uses as much as digits as its factorization.

190811681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4059870.

The product of its (nonzero) digits is 3456, while the sum is 35.

The square root of 190811681 is about 13813.4601385750. The cubic root of 190811681 is about 575.7071888555.

The spelling of 190811681 in words is "one hundred ninety million, eight hundred eleven thousand, six hundred eighty-one".