66680725 has 12 divisors (see below), whose sum is σ = 82797156. Its totient is φ = 53271680.

The previous prime is 66680723. The next prime is 66680729. The reversal of 66680725 is 52708666.

It can be written as a sum of positive squares in 6 ways, for example, as 27468081 + 39212644 = 5241^2 + 6262^2 .

It is not a de Polignac number, because 66680725 - 2¹ = 66680723 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66680723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24009 + ... + 26641.

It is an arithmetic number, because the mean of its divisors is an integer number (6899763).

Almost surely, 2^66680725 is an apocalyptic number.

It is an amenable number.

66680725 is a deficient number, since it is larger than the sum of its proper divisors (16116431).

66680725 is a wasteful number, since it uses less digits than its factorization.

66680725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3656 (or 3651 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The square root of 66680725 is about 8165.8266574793. The cubic root of 66680725 is about 405.5086329094.

The spelling of 66680725 in words is "sixty-six million, six hundred eighty thousand, seven hundred twenty-five".