9971778 has 16 divisors (see below), whose sum is σ = 19979136. Its totient is φ = 3318000.

The previous prime is 9971761. The next prime is 9971779. The reversal of 9971778 is 8771799.

It is not an unprimeable number, because it can be changed into a prime (9971779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3400 + ... + 5612.

It is an arithmetic number, because the mean of its divisors is an integer number (1248696).

Almost surely, 2^9971778 is an apocalyptic number.

9971778 is an abundant number, since it is smaller than the sum of its proper divisors (10007358).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9971778 is a wasteful number, since it uses less digits than its factorization.

9971778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2969.

The product of its digits is 222264, while the sum is 48.

The square root of 9971778 is about 3157.8122173429. The cubic root of 9971778 is about 215.2406031880.

It can be divided in two parts, 997 and 1778, that added together give a triangular number (2775 = T₇₄).

The spelling of 9971778 in words is "nine million, nine hundred seventy-one thousand, seven hundred seventy-eight".