66538202500 has 405 divisors, whose sum is σ = 188866355139. Its totient is φ = 20429640000.

The previous prime is 66538202477. The next prime is 66538202501. The reversal of 66538202500 is 520283566.

It is a happy number.

The square root of 66538202500 is 257950.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 5216595076 + 61321607424 = 72226^2 + 247632^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66538202500.

It is not an unprimeable number, because it can be changed into a prime (66538202501) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 993107467 + ... + 993107533.

Almost surely, 2^66538202500 is an apocalyptic number.

66538202500 is the 257950-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66538202500

66538202500 is an abundant number, since it is smaller than the sum of its proper divisors (122328152639).

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

66538202500 is a wasteful number, since it uses less digits than its factorization.

66538202500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 66538202500 in words is "sixty-six billion, five hundred thirty-eight million, two hundred two thousand, five hundred".