766778684281 has 3 divisors (see below), whose sum is σ = 766779559941. Its totient is φ = 766777808622.

The previous prime is 766778684239. The next prime is 766778684291. The reversal of 766778684281 is 182486877667.

The square root of 766778684281 is 875659.

It is a perfect power (a square), and thus also a powerful number.

766778684281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 766778684281 - 2³¹ = 764631200633 is a prime.

It is a super-2 number, since 2×766778684281² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 766778684281.

It is not an unprimeable number, because it can be changed into a prime (766778684291) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 437830 + ... + 1313488.

It is an arithmetic number, because the mean of its divisors is an integer number (255593186647).

Almost surely, 2^766778684281 is an apocalyptic number.

766778684281 is the 875659-th square number.

766778684281 is the 437830-th centered octagonal number.

It is an amenable number.

766778684281 is a deficient number, since it is larger than the sum of its proper divisors (875660).

766778684281 is an frugal number, since it uses more digits than its factorization.

766778684281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751318 (or 875659 counting only the distinct ones).

The product of its digits is 303464448, while the sum is 70.

The spelling of 766778684281 in words is "seven hundred sixty-six billion, seven hundred seventy-eight million, six hundred eighty-four thousand, two hundred eighty-one".