77781016436 has 12 divisors (see below), whose sum is σ = 144123648228. Its totient is φ = 36602831232.

The previous prime is 77781016399. The next prime is 77781016549. The reversal of 77781016436 is 63461018777.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21317752036 + 56463264400 = 146006^2 + 237620^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 571919171 + ... + 571919306.

It is an arithmetic number, because the mean of its divisors is an integer number (12010304019).

Almost surely, 2^77781016436 is an apocalyptic number.

It is an amenable number.

77781016436 is a deficient number, since it is larger than the sum of its proper divisors (66342631792).

77781016436 is a wasteful number, since it uses less digits than its factorization.

77781016436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1143838498 (or 1143838496 counting only the distinct ones).

The product of its (nonzero) digits is 1185408, while the sum is 50.

The spelling of 77781016436 in words is "seventy-seven billion, seven hundred eighty-one million, sixteen thousand, four hundred thirty-six".