778287426436 has 27 divisors (see below), whose sum is σ = 1474875113733. Its totient is φ = 359198994960.

The previous prime is 778287426431. The next prime is 778287426463. The reversal of 778287426436 is 634624782877.

The square root of 778287426436 is 882206.

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

778287426436 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 115131276100 + 663156150336 = 339310^2 + 814344^2 .

It is a super-2 number, since 2×778287426436² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (778287426431) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22920391 + ... + 22954321.

Almost surely, 2^778287426436 is an apocalyptic number.

778287426436 is the 882206-th square number.

It is an amenable number.

778287426436 is a deficient number, since it is larger than the sum of its proper divisors (696587687297).

778287426436 is an frugal number, since it uses more digits than its factorization.

778287426436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67892 (or 33946 counting only the distinct ones).

The product of its digits is 151732224, while the sum is 64.

Multiplying 778287426436 by its sum of digits (64), we get a square (49810395291904 = 7057648²).

The spelling of 778287426436 in words is "seven hundred seventy-eight billion, two hundred eighty-seven million, four hundred twenty-six thousand, four hundred thirty-six".