1990941081 has 8 divisors (see below), whose sum is σ = 2655332544. Its totient is φ = 1326921840.

The previous prime is 1990941079. The next prime is 1990941091. The reversal of 1990941081 is 1801490991.

It is a happy number.

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

It is not a de Polignac number, because 1990941081 - 2¹ = 1990941079 is a prime.

It is a super-2 number, since 2×1990941081² = 7927692776026897122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1990941041) 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, 80325 + ... + 102146.

It is an arithmetic number, because the mean of its divisors is an integer number (331916568).

Almost surely, 2^1990941081 is an apocalyptic number.

It is an amenable number.

1990941081 is a deficient number, since it is larger than the sum of its proper divisors (664391463).

1990941081 is a wasteful number, since it uses less digits than its factorization.

1990941081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186111.

The product of its (nonzero) digits is 23328, while the sum is 42.

The square root of 1990941081 is about 44619.9628081423. The cubic root of 1990941081 is about 1258.0159167958.

The spelling of 1990941081 in words is "one billion, nine hundred ninety million, nine hundred forty-one thousand, eighty-one".