77377921 has 4 divisors (see below), whose sum is σ = 77870932. Its totient is φ = 76884912.

The previous prime is 77377919. The next prime is 77377943. The reversal of 77377921 is 12977377.

It is a happy number.

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 58982400 + 18395521 = 7680^2 + 4289^2 .

It is a cyclic number.

It is not a de Polignac number, because 77377921 - 2¹ = 77377919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77377961) 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 in 3 ways as a sum of consecutive naturals, for example, 246270 + ... + 246583.

It is an arithmetic number, because the mean of its divisors is an integer number (19467733).

Almost surely, 2^77377921 is an apocalyptic number.

It is an amenable number.

77377921 is a deficient number, since it is larger than the sum of its proper divisors (493011).

77377921 is a wasteful number, since it uses less digits than its factorization.

77377921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493010.

The product of its digits is 129654, while the sum is 43.

The square root of 77377921 is about 8796.4720769181. The cubic root of 77377921 is about 426.1269670109.

The spelling of 77377921 in words is "seventy-seven million, three hundred seventy-seven thousand, nine hundred twenty-one".