77903040821 has 8 divisors (see below), whose sum is σ = 82492015320. Its totient is φ = 73314782208.

The previous prime is 77903040781. The next prime is 77903040841. The reversal of 77903040821 is 12804030977.

It can be written as a sum of positive squares in 4 ways, for example, as 1235522500 + 76667518321 = 35150^2 + 276889^2 .

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-77903040821 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 (77903040841) 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, 53735 + ... + 398363.

It is an arithmetic number, because the mean of its divisors is an integer number (10311501915).

Almost surely, 2^77903040821 is an apocalyptic number.

It is an amenable number.

77903040821 is a deficient number, since it is larger than the sum of its proper divisors (4588974499).

77903040821 is a wasteful number, since it uses less digits than its factorization.

77903040821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357943.

The product of its (nonzero) digits is 84672, while the sum is 41.

The spelling of 77903040821 in words is "seventy-seven billion, nine hundred three million, forty thousand, eight hundred twenty-one".