77621689477 has 4 divisors (see below), whose sum is σ = 80125614976. Its totient is φ = 75117763980.

The previous prime is 77621689471. The next prime is 77621689489. The reversal of 77621689477 is 77498612677.

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.

It is a cyclic number.

It is not a de Polignac number, because 77621689477 - 2²⁷ = 77487471749 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 (77621689471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1251962703 + ... + 1251962764.

It is an arithmetic number, because the mean of its divisors is an integer number (20031403744).

Almost surely, 2^77621689477 is an apocalyptic number.

It is an amenable number.

77621689477 is a deficient number, since it is larger than the sum of its proper divisors (2503925499).

77621689477 is a wasteful number, since it uses less digits than its factorization.

77621689477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2503925498.

The product of its digits is 49787136, while the sum is 64.

The spelling of 77621689477 in words is "seventy-seven billion, six hundred twenty-one million, six hundred eighty-nine thousand, four hundred seventy-seven".