66861963 has 16 divisors (see below), whose sum is σ = 113205760. Its totient is φ = 38206728.

The previous prime is 66861961. The next prime is 66861973. The reversal of 66861963 is 36916866.

It is not a de Polignac number, because 66861963 - 2¹ = 66861961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66861961) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 176695 + ... + 177072.

It is an arithmetic number, because the mean of its divisors is an integer number (7075360).

Almost surely, 2^66861963 is an apocalyptic number.

66861963 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

66861963 is a deficient number, since it is larger than the sum of its proper divisors (46343797).

66861963 is a wasteful number, since it uses less digits than its factorization.

66861963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353783 (or 353777 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 66861963 is about 8176.9164726075. The cubic root of 66861963 is about 405.8756909504.

It can be divided in two parts, 6686 and 1963, that added together give a square (8649 = 93²).

The spelling of 66861963 in words is "sixty-six million, eight hundred sixty-one thousand, nine hundred sixty-three".