66651660435642 has 16 divisors (see below), whose sum is σ = 133305730471872. Its totient is φ = 22216818545120.

The previous prime is 66651660435641. The next prime is 66651660435683. The reversal of 66651660435642 is 24653406615666.

It is not an unprimeable number, because it can be changed into a prime (66651660435641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100040334 + ... + 100704377.

It is an arithmetic number, because the mean of its divisors is an integer number (8331608154492).

Almost surely, 2^{66651660435642} is an apocalyptic number.

66651660435642 is an abundant number, since it is smaller than the sum of its proper divisors (66654070036230).

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

66651660435642 is a wasteful number, since it uses less digits than its factorization.

66651660435642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200800053.

The product of its (nonzero) digits is 111974400, while the sum is 60.

The spelling of 66651660435642 in words is "sixty-six trillion, six hundred fifty-one billion, six hundred sixty million, four hundred thirty-five thousand, six hundred forty-two".