77383921 has 4 divisors (see below), whose sum is σ = 77552244. Its totient is φ = 77215600.

The previous prime is 77383913. The next prime is 77383939. The reversal of 77383921 is 12938377.

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 51322896 + 26061025 = 7164^2 + 5105^2 .

It is a cyclic number.

It is not a de Polignac number, because 77383921 - 2³ = 77383913 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77383951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83470 + ... + 84391.

It is an arithmetic number, because the mean of its divisors is an integer number (19388061).

Almost surely, 2^77383921 is an apocalyptic number.

It is an amenable number.

77383921 is a deficient number, since it is larger than the sum of its proper divisors (168323).

77383921 is a wasteful number, since it uses less digits than its factorization.

77383921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168322.

The product of its digits is 63504, while the sum is 40.

The square root of 77383921 is about 8796.8131161234. The cubic root of 77383921 is about 426.1379809008.

The spelling of 77383921 in words is "seventy-seven million, three hundred eighty-three thousand, nine hundred twenty-one".