77392421 has 4 divisors (see below), whose sum is σ = 77793612. Its totient is φ = 76991232.

The previous prime is 77392411. The next prime is 77392423. The reversal of 77392421 is 12429377.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12429377 = 211 ⋅58907.

It can be written as a sum of positive squares in 2 ways, for example, as 12348196 + 65044225 = 3514^2 + 8065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77392421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77392423) 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, 200306 + ... + 200691.

It is an arithmetic number, because the mean of its divisors is an integer number (19448403).

Almost surely, 2^77392421 is an apocalyptic number.

It is an amenable number.

77392421 is a deficient number, since it is larger than the sum of its proper divisors (401191).

77392421 is a wasteful number, since it uses less digits than its factorization.

77392421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401190.

The product of its digits is 21168, while the sum is 35.

The square root of 77392421 is about 8797.2962323659. The cubic root of 77392421 is about 426.1535829371.

The spelling of 77392421 in words is "seventy-seven million, three hundred ninety-two thousand, four hundred twenty-one".