9891788977 has 16 divisors (see below), whose sum is σ = 11707666432. Its totient is φ = 8178388560.

The previous prime is 9891788971. The next prime is 9891788999. The reversal of 9891788977 is 7798871989.

It is a cyclic number.

It is not a de Polignac number, because 9891788977 - 2³ = 9891788969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9891788971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7623 + ... + 140860.

It is an arithmetic number, because the mean of its divisors is an integer number (731729152).

Almost surely, 2^9891788977 is an apocalyptic number.

It is an amenable number.

9891788977 is a deficient number, since it is larger than the sum of its proper divisors (1815877455).

9891788977 is a wasteful number, since it uses less digits than its factorization.

9891788977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148828.

The product of its digits is 128024064, while the sum is 73.

The square root of 9891788977 is about 99457.4732084020. The cubic root of 9891788977 is about 2146.6353702079.

The spelling of 9891788977 in words is "nine billion, eight hundred ninety-one million, seven hundred eighty-eight thousand, nine hundred seventy-seven".