77121 has 24 divisors (see below), whose sum is σ = 131040. Its totient is φ = 43200.

The previous prime is 77101. The next prime is 77137. The reversal of 77121 is 12177.

It is not a de Polignac number, because 77121 - 2¹⁴ = 60737 is a prime.

It is an Ulam number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 77094 and 77103.

It is not an unprimeable number, because it can be changed into a prime (77101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1861 + ... + 1901.

It is an arithmetic number, because the mean of its divisors is an integer number (5460).

2⁷⁷¹²¹ is an apocalyptic number.

It is an amenable number.

77121 is a deficient number, since it is larger than the sum of its proper divisors (53919).

77121 is a wasteful number, since it uses less digits than its factorization.

77121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 74 counting only the distinct ones).

The product of its digits is 98, while the sum is 18.

The square root of 77121 is about 277.7066797900. The cubic root of 77121 is about 42.5654815263.

Adding to 77121 its reverse (12177), we get a palindrome (89298).

The spelling of 77121 in words is "seventy-seven thousand, one hundred twenty-one", and thus it is an iban number.