9981494978 has 64 divisors (see below), whose sum is σ = 19118453760. Its totient is φ = 3801434112.

The previous prime is 9981494969. The next prime is 9981494987. The reversal of 9981494978 is 8794941899.

It is an interprime number because it is at equal distance from previous prime (9981494969) and next prime (9981494987).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1934450 + ... + 1939602.

It is an arithmetic number, because the mean of its divisors is an integer number (298725840).

Almost surely, 2^9981494978 is an apocalyptic number.

9981494978 is a deficient number, since it is larger than the sum of its proper divisors (9136958782).

9981494978 is a wasteful number, since it uses less digits than its factorization.

9981494978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5571.

The product of its digits is 47029248, while the sum is 68.

The square root of 9981494978 is about 99907.4320458693. The cubic root of 9981494978 is about 2153.1049407484.

The spelling of 9981494978 in words is "nine billion, nine hundred eighty-one million, four hundred ninety-four thousand, nine hundred seventy-eight".