77985993 has 4 divisors (see below), whose sum is σ = 103981328. Its totient is φ = 51990660.

The previous prime is 77985991. The next prime is 77985997. The reversal of 77985993 is 39958977.

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.

It is not a de Polignac number, because 77985993 - 2¹ = 77985991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77985991) 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, 12997663 + ... + 12997668.

It is an arithmetic number, because the mean of its divisors is an integer number (25995332).

Almost surely, 2^77985993 is an apocalyptic number.

It is an amenable number.

77985993 is a deficient number, since it is larger than the sum of its proper divisors (25995335).

77985993 is a wasteful number, since it uses less digits than its factorization.

77985993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25995334.

The product of its digits is 4286520, while the sum is 57.

The square root of 77985993 is about 8830.9678405031. The cubic root of 77985993 is about 427.2402909421.

The spelling of 77985993 in words is "seventy-seven million, nine hundred eighty-five thousand, nine hundred ninety-three".