9981986977 has 4 divisors (see below), whose sum is σ = 10225450116. Its totient is φ = 9738523840.

The previous prime is 9981986969. The next prime is 9981986983. The reversal of 9981986977 is 7796891899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7796891899 = 47 ⋅165891317.

It can be written as a sum of positive squares in 2 ways, for example, as 2817380241 + 7164606736 = 53079^2 + 84644^2 .

It is a cyclic number.

It is not a de Polignac number, because 9981986977 - 2³ = 9981986969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9981986957) 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, 121731508 + ... + 121731589.

It is an arithmetic number, because the mean of its divisors is an integer number (2556362529).

Almost surely, 2^9981986977 is an apocalyptic number.

It is an amenable number.

9981986977 is a deficient number, since it is larger than the sum of its proper divisors (243463139).

9981986977 is a wasteful number, since it uses less digits than its factorization.

9981986977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243463138.

The product of its digits is 123451776, while the sum is 73.

The square root of 9981986977 is about 99909.8942898050. The cubic root of 9981986977 is about 2153.1403164804.

The spelling of 9981986977 in words is "nine billion, nine hundred eighty-one million, nine hundred eighty-six thousand, nine hundred seventy-seven".