77800444438 has 4 divisors (see below), whose sum is σ = 116700666660. Its totient is φ = 38900222218.

The previous prime is 77800444409. The next prime is 77800444439. The reversal of 77800444438 is 83444400877.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83444400877 = 31 ⋅2691754867.

It is a junction number, because it is equal to n+sod(n) for n = 77800444391 and 77800444400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77800444439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19450111108 + ... + 19450111111.

It is an arithmetic number, because the mean of its divisors is an integer number (29175166665).

Almost surely, 2^77800444438 is an apocalyptic number.

77800444438 is a deficient number, since it is larger than the sum of its proper divisors (38900222222).

77800444438 is a wasteful number, since it uses less digits than its factorization.

77800444438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38900222221.

The product of its (nonzero) digits is 2408448, while the sum is 49.

The spelling of 77800444438 in words is "seventy-seven billion, eight hundred million, four hundred forty-four thousand, four hundred thirty-eight".