66257613 has 6 divisors (see below), whose sum is σ = 95705454. Its totient is φ = 44171736.

The previous prime is 66257593. The next prime is 66257657. The reversal of 66257613 is 31675266.

It can be written as a sum of positive squares in only one way, i.e., 53319204 + 12938409 = 7302^2 + 3597^2 .

It is not a de Polignac number, because 66257613 - 2⁹ = 66257101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66257683) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3680970 + ... + 3680987.

It is an arithmetic number, because the mean of its divisors is an integer number (15950909).

Almost surely, 2^66257613 is an apocalyptic number.

It is an amenable number.

66257613 is a deficient number, since it is larger than the sum of its proper divisors (29447841).

66257613 is a wasteful number, since it uses less digits than its factorization.

66257613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7361963 (or 7361960 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 66257613 is about 8139.8779474879. The cubic root of 66257613 is about 404.6491153836.

The spelling of 66257613 in words is "sixty-six million, two hundred fifty-seven thousand, six hundred thirteen".