66551100625 has 45 divisors (see below), whose sum is σ = 88487689719. Its totient is φ = 50026512000.

The previous prime is 66551100619. The next prime is 66551100641. The reversal of 66551100625 is 52600115566.

The square root of 66551100625 is 257975.

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

It can be written as a sum of positive squares in 7 ways, for example, as 32500517841 + 34050582784 = 180279^2 + 184528^2 .

It is not a de Polignac number, because 66551100625 - 2¹¹ = 66551098577 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 109639072 + ... + 109639678.

Almost surely, 2^66551100625 is an apocalyptic number.

66551100625 is the 257975-th square number.

66551100625 is the 128988-th centered octagonal number.

It is an amenable number.

66551100625 is a deficient number, since it is larger than the sum of its proper divisors (21936589094).

66551100625 is an frugal number, since it uses more digits than its factorization.

66551100625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1268 (or 629 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 66551100625 in words is "sixty-six billion, five hundred fifty-one million, one hundred thousand, six hundred twenty-five".