77920387 has 4 divisors (see below), whose sum is σ = 82021480. Its totient is φ = 73819296.

The previous prime is 77920369. The next prime is 77920399. The reversal of 77920387 is 78302977.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 77920387 - 2⁷ = 77920259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77920327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2050518 + ... + 2050555.

It is an arithmetic number, because the mean of its divisors is an integer number (20505370).

Almost surely, 2^77920387 is an apocalyptic number.

77920387 is a deficient number, since it is larger than the sum of its proper divisors (4101093).

77920387 is a wasteful number, since it uses less digits than its factorization.

77920387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4101092.

The product of its (nonzero) digits is 148176, while the sum is 43.

The square root of 77920387 is about 8827.2525170633. The cubic root of 77920387 is about 427.1204515149.

The spelling of 77920387 in words is "seventy-seven million, nine hundred twenty thousand, three hundred eighty-seven".