66963978 has 24 divisors (see below), whose sum is σ = 145595268. Its totient is φ = 22243392.

The previous prime is 66963977. The next prime is 66963979. The reversal of 66963978 is 87936966.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66963977) and next prime (66963979).

It can be written as a sum of positive squares in 2 ways, for example, as 66048129 + 915849 = 8127^2 + 957^2 .

It is not an unprimeable number, because it can be changed into a prime (66963973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1075 + ... + 11622.

Almost surely, 2^66963978 is an apocalyptic number.

66963978 is an abundant number, since it is smaller than the sum of its proper divisors (78631290).

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

66963978 is a wasteful number, since it uses less digits than its factorization.

66963978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12998 (or 12995 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 54.

The square root of 66963978 is about 8183.1520821747. The cubic root of 66963978 is about 406.0820083961.

The spelling of 66963978 in words is "sixty-six million, nine hundred sixty-three thousand, nine hundred seventy-eight".