77821039807 has 16 divisors (see below), whose sum is σ = 89452097280. Its totient is φ = 66319273152.

The previous prime is 77821039801. The next prime is 77821039883. The reversal of 77821039807 is 70893012877.

It is a cyclic number.

It is not a de Polignac number, because 77821039807 - 2⁷ = 77821039679 is a prime.

It is a super-2 number, since 2×77821039807² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77821039801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1079044 + ... + 1148902.

It is an arithmetic number, because the mean of its divisors is an integer number (5590756080).

Almost surely, 2^77821039807 is an apocalyptic number.

77821039807 is a deficient number, since it is larger than the sum of its proper divisors (11631057473).

77821039807 is a wasteful number, since it uses less digits than its factorization.

77821039807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70782.

The product of its (nonzero) digits is 1185408, while the sum is 52.

The spelling of 77821039807 in words is "seventy-seven billion, eight hundred twenty-one million, thirty-nine thousand, eight hundred seven".