77490772821 has 32 divisors (see below), whose sum is σ = 143128704000. Its totient is φ = 40254945840.

The previous prime is 77490772787. The next prime is 77490772831. The reversal of 77490772821 is 12827709477.

77490772821 is a `hidden beast` number, since 7 + 7 + 490 + 7 + 72 + 82 + 1 = 666.

It is not a de Polignac number, because 77490772821 - 2¹⁰ = 77490771797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77490772831) 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 31 ways as a sum of consecutive naturals, for example, 18634471 + ... + 18638628.

It is an arithmetic number, because the mean of its divisors is an integer number (4472772000).

Almost surely, 2^77490772821 is an apocalyptic number.

It is an amenable number.

77490772821 is a deficient number, since it is larger than the sum of its proper divisors (65637931179).

77490772821 is a wasteful number, since it uses less digits than its factorization.

77490772821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37273126 (or 37273120 counting only the distinct ones).

The product of its (nonzero) digits is 2765952, while the sum is 54.

The spelling of 77490772821 in words is "seventy-seven billion, four hundred ninety million, seven hundred seventy-two thousand, eight hundred twenty-one".