66204878131 has 16 divisors (see below), whose sum is σ = 77508689920. Its totient is φ = 55377211680.

The previous prime is 66204878107. The next prime is 66204878137. The reversal of 66204878131 is 13187840266.

It is a happy number.

It is not a de Polignac number, because 66204878131 - 2¹⁹ = 66204353843 is a prime.

It is a super-2 number, since 2×66204878131² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66204878137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 556191 + ... + 664648.

It is an arithmetic number, because the mean of its divisors is an integer number (4844293120).

Almost surely, 2^66204878131 is an apocalyptic number.

66204878131 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

66204878131 is a deficient number, since it is larger than the sum of its proper divisors (11303811789).

66204878131 is a wasteful number, since it uses less digits than its factorization.

66204878131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1221034.

The product of its (nonzero) digits is 387072, while the sum is 46.

The spelling of 66204878131 in words is "sixty-six billion, two hundred four million, eight hundred seventy-eight thousand, one hundred thirty-one".