981994651 has 16 divisors (see below), whose sum is σ = 1134869760. Its totient is φ = 840322080.

The previous prime is 981994627. The next prime is 981994661. The reversal of 981994651 is 156499189.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 981994651 - 2²⁵ = 948440219 is a prime.

It is a super-2 number, since 2×981994651² = 1928626989185223602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981994621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17850 + ... + 47776.

It is an arithmetic number, because the mean of its divisors is an integer number (70929360).

Almost surely, 2^981994651 is an apocalyptic number.

981994651 is a deficient number, since it is larger than the sum of its proper divisors (152875109).

981994651 is a wasteful number, since it uses less digits than its factorization.

981994651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30114.

The product of its digits is 699840, while the sum is 52.

The square root of 981994651 is about 31336.7938851440. The cubic root of 981994651 is about 993.9618308967.

The spelling of 981994651 in words is "nine hundred eighty-one million, nine hundred ninety-four thousand, six hundred fifty-one".