77793091890 has 64 divisors (see below), whose sum is σ = 193188844800. Its totient is φ = 20024573184.

The previous prime is 77793091847. The next prime is 77793091891. The reversal of 77793091890 is 9819039777.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (77793091891) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4701051 + ... + 4717569.

It is an arithmetic number, because the mean of its divisors is an integer number (3018575700).

Almost surely, 2^77793091890 is an apocalyptic number.

77793091890 is an abundant number, since it is smaller than the sum of its proper divisors (115395752910).

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

77793091890 is a wasteful number, since it uses less digits than its factorization.

77793091890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21971.

The product of its (nonzero) digits is 6001128, while the sum is 60.

The spelling of 77793091890 in words is "seventy-seven billion, seven hundred ninety-three million, ninety-one thousand, eight hundred ninety".