77330921 has 4 divisors (see below), whose sum is σ = 77610372. Its totient is φ = 77051472.

The previous prime is 77330873. The next prime is 77330923. The reversal of 77330921 is 12903377.

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 49505296 + 27825625 = 7036^2 + 5275^2 .

It is a cyclic number.

It is not a de Polignac number, because 77330921 - 2²² = 73136617 is a prime.

It is a super-3 number, since 3×77330921³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77330923) 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, 139310 + ... + 139863.

It is an arithmetic number, because the mean of its divisors is an integer number (19402593).

Almost surely, 2^77330921 is an apocalyptic number.

It is an amenable number.

77330921 is a deficient number, since it is larger than the sum of its proper divisors (279451).

77330921 is a wasteful number, since it uses less digits than its factorization.

77330921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279450.

The product of its (nonzero) digits is 7938, while the sum is 32.

The square root of 77330921 is about 8793.8001455571. The cubic root of 77330921 is about 426.0406718352.

The spelling of 77330921 in words is "seventy-seven million, three hundred thirty thousand, nine hundred twenty-one".