77221553620 has 12 divisors (see below), whose sum is σ = 162165262644. Its totient is φ = 30888621440.

The previous prime is 77221553599. The next prime is 77221553621. The reversal of 77221553620 is 2635512277.

It can be written as a sum of positive squares in 2 ways, for example, as 41774454544 + 35447099076 = 204388^2 + 188274^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77221553621) 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, 1930538821 + ... + 1930538860.

It is an arithmetic number, because the mean of its divisors is an integer number (13513771887).

Almost surely, 2^77221553620 is an apocalyptic number.

It is an amenable number.

77221553620 is an abundant number, since it is smaller than the sum of its proper divisors (84943709024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77221553620 is a wasteful number, since it uses less digits than its factorization.

77221553620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3861077690 (or 3861077688 counting only the distinct ones).

The product of its (nonzero) digits is 176400, while the sum is 40.

The spelling of 77221553620 in words is "seventy-seven billion, two hundred twenty-one million, five hundred fifty-three thousand, six hundred twenty".