78399486 has 48 divisors (see below), whose sum is σ = 186496128. Its totient is φ = 23605200.

The previous prime is 78399473. The next prime is 78399547. The reversal of 78399486 is 68499387.

78399486 is a `hidden beast` number, since 78 + 3 + 99 + 486 = 666.

It is a super-2 number, since 2×78399486² = 12292958810128392, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31881 + ... + 34251.

It is an arithmetic number, because the mean of its divisors is an integer number (3885336).

Almost surely, 2^78399486 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78399486, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93248064).

78399486 is an abundant number, since it is smaller than the sum of its proper divisors (108096642).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78399486 is a wasteful number, since it uses less digits than its factorization.

78399486 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2557 (or 2554 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 54.

The square root of 78399486 is about 8854.3484232325. The cubic root of 78399486 is about 427.9940568948.

Subtracting from 78399486 its reverse (68499387), we obtain a palindrome (9900099).

The spelling of 78399486 in words is "seventy-eight million, three hundred ninety-nine thousand, four hundred eighty-six".