991683081 has 15 divisors (see below), whose sum is σ = 1481826621. Its totient is φ = 660933108.

The previous prime is 991683079. The next prime is 991683107. The reversal of 991683081 is 180386199.

The square root of 991683081 is 31491.

It is a perfect power (a square), and thus also a powerful number.

991683081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 991683081 - 2¹ = 991683079 is a prime.

It is a super-2 number, since 2×991683081² = 1966870666283305122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991683041) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 281670 + ... + 285168.

Almost surely, 2^991683081 is an apocalyptic number.

991683081 is the 31491-st square number.

991683081 is the 15746-th centered octagonal number.

It is an amenable number.

991683081 is a deficient number, since it is larger than the sum of its proper divisors (490143540).

991683081 is an frugal number, since it uses more digits than its factorization.

991683081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7010 (or 3502 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The cubic root of 991683081 is about 997.2199722744.

The spelling of 991683081 in words is "nine hundred ninety-one million, six hundred eighty-three thousand, eighty-one".