66920516100 has 81 divisors (see below), whose sum is σ = 209782968213. Its totient is φ = 17843401440.

The previous prime is 66920516077. The next prime is 66920516107. The reversal of 66920516100 is 161502966.

The square root of 66920516100 is 258690.

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

It can be written as a sum of positive squares in only one way, i.e., 24091385796 + 42829130304 = 155214^2 + 206952^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (66920516107) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7756389 + ... + 7765011.

Almost surely, 2^66920516100 is an apocalyptic number.

66920516100 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

66920516100 is the 258690-th square number.

It is an amenable number.

66920516100 is an abundant number, since it is smaller than the sum of its proper divisors (142862452113).

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

66920516100 is an equidigital number, since it uses as much as digits as its factorization.

66920516100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17266 (or 8633 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

Multiplying 66920516100 by its sum of digits (36), we get a square (2409138579600 = 1552140²).

66920516100 divided by its sum of digits (36) gives a square (1858903225 = 43115²).

The spelling of 66920516100 in words is "sixty-six billion, nine hundred twenty million, five hundred sixteen thousand, one hundred".