78619905 has 96 divisors (see below), whose sum is σ = 170666496. Its totient is φ = 32596992.

The previous prime is 78619897. The next prime is 78619909. The reversal of 78619905 is 50991687.

It is not a de Polignac number, because 78619905 - 2³ = 78619897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78619909) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 298804 + ... + 299066.

It is an arithmetic number, because the mean of its divisors is an integer number (1777776).

Almost surely, 2^78619905 is an apocalyptic number.

It is an amenable number.

78619905 is an abundant number, since it is smaller than the sum of its proper divisors (92046591).

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

78619905 is a wasteful number, since it uses less digits than its factorization.

78619905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367 (or 364 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 78619905 is about 8866.7866219956. The cubic root of 78619905 is about 428.3947812476.

It can be divided in two parts, 78619 and 905, that added together give a square (79524 = 282²).

The spelling of 78619905 in words is "seventy-eight million, six hundred nineteen thousand, nine hundred five".