78287899 has 4 divisors (see below), whose sum is σ = 78353136. Its totient is φ = 78222664.

The previous prime is 78287887. The next prime is 78287933. The reversal of 78287899 is 99878287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99878287 = 419 ⋅238373.

It is a cyclic number.

It is not a de Polignac number, because 78287899 - 2¹⁹ = 77763611 is a prime.

It is a super-2 number, since 2×78287899² = 12257990259668402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78287879) 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, 30784 + ... + 33229.

It is an arithmetic number, because the mean of its divisors is an integer number (19588284).

Almost surely, 2^78287899 is an apocalyptic number.

78287899 is a deficient number, since it is larger than the sum of its proper divisors (65237).

78287899 is a wasteful number, since it uses less digits than its factorization.

78287899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65236.

The product of its digits is 4064256, while the sum is 58.

The square root of 78287899 is about 8848.0449252928. The cubic root of 78287899 is about 427.7909039931.

The spelling of 78287899 in words is "seventy-eight million, two hundred eighty-seven thousand, eight hundred ninety-nine".