65978874 has 84 divisors (see below), whose sum is σ = 162553146. Its totient is φ = 19957104.

The previous prime is 65978867. The next prime is 65978909. The reversal of 65978874 is 47887956.

It can be written as a sum of positive squares in only one way, i.e., 63441225 + 2537649 = 7965^2 + 1593^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 65978874.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 1118257 + ... + 1118315.

Almost surely, 2^65978874 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65978874, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81276573).

65978874 is an abundant number, since it is smaller than the sum of its proper divisors (96574272).

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

65978874 is an equidigital number, since it uses as much as digits as its factorization.

65978874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 77 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The square root of 65978874 is about 8122.7380851533. The cubic root of 65978874 is about 404.0808786544.

The spelling of 65978874 in words is "sixty-five million, nine hundred seventy-eight thousand, eight hundred seventy-four".