77739121 has 2 divisors, whose sum is σ = 77739122. Its totient is φ = 77739120.

The previous prime is 77739091. The next prime is 77739131. The reversal of 77739121 is 12193777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47610000 + 30129121 = 6900^2 + 5489^2 .

It is a cyclic number.

It is not a de Polignac number, because 77739121 - 2²⁵ = 44184689 is a prime.

It is not a weakly prime, because it can be changed into another prime (77739131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38869560 + 38869561.

It is an arithmetic number, because the mean of its divisors is an integer number (38869561).

Almost surely, 2^77739121 is an apocalyptic number.

It is an amenable number.

77739121 is a deficient number, since it is larger than the sum of its proper divisors (1).

77739121 is an equidigital number, since it uses as much as digits as its factorization.

77739121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18522, while the sum is 37.

The square root of 77739121 is about 8816.9791311991. The cubic root of 77739121 is about 426.7889912800.

The spelling of 77739121 in words is "seventy-seven million, seven hundred thirty-nine thousand, one hundred twenty-one".