77558450638 has 4 divisors (see below), whose sum is σ = 116337675960. Its totient is φ = 38779225318.

The previous prime is 77558450633. The next prime is 77558450663. The reversal of 77558450638 is 83605485577.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77558450633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19389612658 + ... + 19389612661.

It is an arithmetic number, because the mean of its divisors is an integer number (29084418990).

Almost surely, 2^77558450638 is an apocalyptic number.

77558450638 is a deficient number, since it is larger than the sum of its proper divisors (38779225322).

77558450638 is a wasteful number, since it uses less digits than its factorization.

77558450638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38779225321.

The product of its (nonzero) digits is 28224000, while the sum is 58.

The spelling of 77558450638 in words is "seventy-seven billion, five hundred fifty-eight million, four hundred fifty thousand, six hundred thirty-eight".