84778399 has 4 divisors (see below), whose sum is σ = 89240440. Its totient is φ = 80316360.

The previous prime is 84778387. The next prime is 84778403. The reversal of 84778399 is 99387748.

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 84778399 - 2⁵ = 84778367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84278399) 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, 2230992 + ... + 2231029.

It is an arithmetic number, because the mean of its divisors is an integer number (22310110).

Almost surely, 2^84778399 is an apocalyptic number.

84778399 is a deficient number, since it is larger than the sum of its proper divisors (4462041).

84778399 is a wasteful number, since it uses less digits than its factorization.

84778399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4462040.

The product of its digits is 3048192, while the sum is 55.

The square root of 84778399 is about 9207.5186125253. The cubic root of 84778399 is about 439.3005398406.

The spelling of 84778399 in words is "eighty-four million, seven hundred seventy-eight thousand, three hundred ninety-nine".