782815866661 has 4 divisors (see below), whose sum is σ = 808067991424. Its totient is φ = 757563741900.

The previous prime is 782815866629. The next prime is 782815866667. The reversal of 782815866661 is 166668518287.

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 a cyclic number.

It is not a de Polignac number, because 782815866661 - 2⁵ = 782815866629 is a prime.

It is a super-2 number, since 2×782815866661² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 782815866593 and 782815866602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (782815866667) 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, 12626062335 + ... + 12626062396.

It is an arithmetic number, because the mean of its divisors is an integer number (202016997856).

Almost surely, 2^782815866661 is an apocalyptic number.

It is an amenable number.

782815866661 is a deficient number, since it is larger than the sum of its proper divisors (25252124763).

782815866661 is a wasteful number, since it uses less digits than its factorization.

782815866661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25252124762.

The product of its digits is 46448640, while the sum is 64.

The spelling of 782815866661 in words is "seven hundred eighty-two billion, eight hundred fifteen million, eight hundred sixty-six thousand, six hundred sixty-one".