780666587 has 4 divisors (see below), whose sum is σ = 786813696. Its totient is φ = 774519480.

The previous prime is 780666553. The next prime is 780666637. The reversal of 780666587 is 785666087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 785666087 = 14029 ⋅56003.

It is a cyclic number.

It is not a de Polignac number, because 780666587 - 2⁸ = 780666331 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (780666487) 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, 3073364 + ... + 3073617.

It is an arithmetic number, because the mean of its divisors is an integer number (196703424).

Almost surely, 2^780666587 is an apocalyptic number.

780666587 is a deficient number, since it is larger than the sum of its proper divisors (6147109).

780666587 is a wasteful number, since it uses less digits than its factorization.

780666587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6147108.

The product of its (nonzero) digits is 3386880, while the sum is 53.

The square root of 780666587 is about 27940.4113606081. The cubic root of 780666587 is about 920.7785576357.

The spelling of 780666587 in words is "seven hundred eighty million, six hundred sixty-six thousand, five hundred eighty-seven".