77665910021 has 8 divisors (see below), whose sum is σ = 88765754880. Its totient is φ = 66567243888.

The previous prime is 77665909999. The next prime is 77665910039. The reversal of 77665910021 is 12001956677.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77665910021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77665910081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148661 + ... + 421226.

It is an arithmetic number, because the mean of its divisors is an integer number (11095719360).

Almost surely, 2^77665910021 is an apocalyptic number.

It is an amenable number.

77665910021 is a deficient number, since it is larger than the sum of its proper divisors (11099844859).

77665910021 is a wasteful number, since it uses less digits than its factorization.

77665910021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589363.

The product of its (nonzero) digits is 158760, while the sum is 44.

The spelling of 77665910021 in words is "seventy-seven billion, six hundred sixty-five million, nine hundred ten thousand, twenty-one".