77122120121 has 4 divisors (see below), whose sum is σ = 77186336244. Its totient is φ = 77057904000.

The previous prime is 77122120081. The next prime is 77122120123. The reversal of 77122120121 is 12102122177.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8301943225 + 68820176896 = 91115^2 + 262336^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77122120121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77122120123) 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, 32106260 + ... + 32108661.

It is an arithmetic number, because the mean of its divisors is an integer number (19296584061).

Almost surely, 2^77122120121 is an apocalyptic number.

It is an amenable number.

77122120121 is a deficient number, since it is larger than the sum of its proper divisors (64216123).

77122120121 is a wasteful number, since it uses less digits than its factorization.

77122120121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64216122.

The product of its (nonzero) digits is 784, while the sum is 26.

Adding to 77122120121 its reverse (12102122177), we get a palindrome (89224242298).

The spelling of 77122120121 in words is "seventy-seven billion, one hundred twenty-two million, one hundred twenty thousand, one hundred twenty-one".