77244491556 has 18 divisors (see below), whose sum is σ = 195256909302. Its totient is φ = 25748163840.

The previous prime is 77244491551. The next prime is 77244491573. The reversal of 77244491556 is 65519444277.

77244491556 is a `hidden beast` number, since 7 + 7 + 2 + 44 + 49 + 1 + 556 = 666.

It can be written as a sum of positive squares in only one way, i.e., 73598264100 + 3646227456 = 271290^2 + 60384^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×77244491556² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77244491551) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 1072840125 + ... + 1072840196.

Almost surely, 2^77244491556 is an apocalyptic number.

It is an amenable number.

77244491556 is an abundant number, since it is smaller than the sum of its proper divisors (118012417746).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77244491556 is a wasteful number, since it uses less digits than its factorization.

77244491556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2145680331 (or 2145680326 counting only the distinct ones).

The product of its digits is 8467200, while the sum is 54.

The spelling of 77244491556 in words is "seventy-seven billion, two hundred forty-four million, four hundred ninety-one thousand, five hundred fifty-six".