66715725 has 24 divisors (see below), whose sum is σ = 112180320. Its totient is φ = 34976320.

The previous prime is 66715717. The next prime is 66715729. The reversal of 66715725 is 52751766.

It is not a de Polignac number, because 66715725 - 2³ = 66715717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66715729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3114 + ... + 11963.

It is an arithmetic number, because the mean of its divisors is an integer number (4674180).

Almost surely, 2^66715725 is an apocalyptic number.

It is an amenable number.

66715725 is a deficient number, since it is larger than the sum of its proper divisors (45464595).

66715725 is a wasteful number, since it uses less digits than its factorization.

66715725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15149 (or 15144 counting only the distinct ones).

The product of its digits is 88200, while the sum is 39.

The square root of 66715725 is about 8167.9694539096. The cubic root of 66715725 is about 405.5795695489.

The spelling of 66715725 in words is "sixty-six million, seven hundred fifteen thousand, seven hundred twenty-five".