66621699960 has 32 divisors (see below), whose sum is σ = 199865100240. Its totient is φ = 17765786624.

The previous prime is 66621699931. The next prime is 66621699967. The reversal of 66621699960 is 6999612666.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a junction number, because it is equal to n+sod(n) for n = 66621699894 and 66621699903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66621699967) 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, 277590297 + ... + 277590536.

Almost surely, 2^66621699960 is an apocalyptic number.

66621699960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66621699960 is an abundant number, since it is smaller than the sum of its proper divisors (133243400280).

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

66621699960 is a wasteful number, since it uses less digits than its factorization.

66621699960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555180847 (or 555180843 counting only the distinct ones).

The product of its (nonzero) digits is 11337408, while the sum is 60.

The spelling of 66621699960 in words is "sixty-six billion, six hundred twenty-one million, six hundred ninety-nine thousand, nine hundred sixty".