66201623550 has 72 divisors (see below), whose sum is σ = 188324169696. Its totient is φ = 16615307520.

The previous prime is 66201623549. The next prime is 66201623581. The reversal of 66201623550 is 5532610266.

It is a happy number.

66201623550 is a `hidden beast` number, since 6 + 6 + 20 + 1 + 623 + 5 + 5 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4319254 + ... + 4334553.

It is an arithmetic number, because the mean of its divisors is an integer number (2615613468).

Almost surely, 2^66201623550 is an apocalyptic number.

66201623550 is an abundant number, since it is smaller than the sum of its proper divisors (122122546146).

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

66201623550 is a wasteful number, since it uses less digits than its factorization.

66201623550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8653842 (or 8653834 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 66201623550 in words is "sixty-six billion, two hundred one million, six hundred twenty-three thousand, five hundred fifty".