77987297 has 4 divisors (see below), whose sum is σ = 78029616. Its totient is φ = 77944980.

The previous prime is 77987281. The next prime is 77987309. The reversal of 77987297 is 79278977.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79278977 = 2909 ⋅27253.

It is a cyclic number.

It is not a de Polignac number, because 77987297 - 2⁴ = 77987281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77987237) 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, 18263 + ... + 22124.

It is an arithmetic number, because the mean of its divisors is an integer number (19507404).

Almost surely, 2^77987297 is an apocalyptic number.

It is an amenable number.

77987297 is a deficient number, since it is larger than the sum of its proper divisors (42319).

77987297 is a wasteful number, since it uses less digits than its factorization.

77987297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42318.

The product of its digits is 3111696, while the sum is 56.

The square root of 77987297 is about 8831.0416712866. The cubic root of 77987297 is about 427.2426722168.

The spelling of 77987297 in words is "seventy-seven million, nine hundred eighty-seven thousand, two hundred ninety-seven".