77807993420921 has 8 divisors (see below), whose sum is σ = 78683610152160. Its totient is φ = 76932407125728.

The previous prime is 77807993420909. The next prime is 77807993420953. The reversal of 77807993420921 is 12902439970877.

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-77807993420921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77807993420821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2447771 + ... + 12712496.

It is an arithmetic number, because the mean of its divisors is an integer number (9835451269020).

Almost surely, 2^{77807993420921} is an apocalyptic number.

It is an amenable number.

77807993420921 is a deficient number, since it is larger than the sum of its proper divisors (875616731239).

77807993420921 is a wasteful number, since it uses less digits than its factorization.

77807993420921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15218023.

The product of its (nonzero) digits is 96018048, while the sum is 68.

The spelling of 77807993420921 in words is "seventy-seven trillion, eight hundred seven billion, nine hundred ninety-three million, four hundred twenty thousand, nine hundred twenty-one".