77263646021 has 4 divisors (see below), whose sum is σ = 77726302752. Its totient is φ = 76800989292.

The previous prime is 77263645999. The next prime is 77263646063. The reversal of 77263646021 is 12064636277.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12064636277 = 167 ⋅72243331.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77263646021 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 (77263642021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231328115 + ... + 231328448.

It is an arithmetic number, because the mean of its divisors is an integer number (19431575688).

Almost surely, 2^77263646021 is an apocalyptic number.

It is an amenable number.

77263646021 is a deficient number, since it is larger than the sum of its proper divisors (462656731).

77263646021 is a wasteful number, since it uses less digits than its factorization.

77263646021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462656730.

The product of its (nonzero) digits is 508032, while the sum is 44.

The spelling of 77263646021 in words is "seventy-seven billion, two hundred sixty-three million, six hundred forty-six thousand, twenty-one".