77870981644 has 24 divisors (see below), whose sum is σ = 138203589888. Its totient is φ = 38387573520.

The previous prime is 77870981633. The next prime is 77870981651. The reversal of 77870981644 is 44618907877.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322792 + ... + 509839.

It is an arithmetic number, because the mean of its divisors is an integer number (5758482912).

Almost surely, 2^77870981644 is an apocalyptic number.

It is an amenable number.

77870981644 is a deficient number, since it is larger than the sum of its proper divisors (60332608244).

77870981644 is a wasteful number, since it uses less digits than its factorization.

77870981644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832965 (or 832963 counting only the distinct ones).

The product of its (nonzero) digits is 18966528, while the sum is 61.

The spelling of 77870981644 in words is "seventy-seven billion, eight hundred seventy million, nine hundred eighty-one thousand, six hundred forty-four".