66513415 has 4 divisors (see below), whose sum is σ = 79816104. Its totient is φ = 53210728.

The previous prime is 66513373. The next prime is 66513479. The reversal of 66513415 is 51431566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66513415 - 2⁷ = 66513287 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6651337 + ... + 6651346.

It is an arithmetic number, because the mean of its divisors is an integer number (19954026).

Almost surely, 2^66513415 is an apocalyptic number.

66513415 is a deficient number, since it is larger than the sum of its proper divisors (13302689).

66513415 is a wasteful number, since it uses less digits than its factorization.

66513415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13302688.

The product of its digits is 10800, while the sum is 31.

The square root of 66513415 is about 8155.5757000962. The cubic root of 66513415 is about 405.1691921244.

The spelling of 66513415 in words is "sixty-six million, five hundred thirteen thousand, four hundred fifteen".