66661513 has 4 divisors (see below), whose sum is σ = 66843520. Its totient is φ = 66479508.

The previous prime is 66661489. The next prime is 66661537. The reversal of 66661513 is 31516666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (66661489) and next prime (66661537).

It is a cyclic number.

It is not a de Polignac number, because 66661513 - 2¹⁷ = 66530441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66661813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90453 + ... + 91186.

It is an arithmetic number, because the mean of its divisors is an integer number (16710880).

Almost surely, 2^66661513 is an apocalyptic number.

It is an amenable number.

66661513 is a deficient number, since it is larger than the sum of its proper divisors (182007).

66661513 is a wasteful number, since it uses less digits than its factorization.

66661513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182006.

The product of its digits is 19440, while the sum is 34.

The square root of 66661513 is about 8164.6502068368. The cubic root of 66661513 is about 405.4696842217.

The spelling of 66661513 in words is "sixty-six million, six hundred sixty-one thousand, five hundred thirteen".