78385655 has 4 divisors (see below), whose sum is σ = 94062792. Its totient is φ = 62708520.

The previous prime is 78385651. The next prime is 78385673. The reversal of 78385655 is 55658387.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 78385655 - 2² = 78385651 is a prime.

It is a super-2 number, since 2×78385655² = 12288621819558050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78385651) 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, 7838561 + ... + 7838570.

It is an arithmetic number, because the mean of its divisors is an integer number (23515698).

Almost surely, 2^78385655 is an apocalyptic number.

78385655 is a deficient number, since it is larger than the sum of its proper divisors (15677137).

78385655 is a wasteful number, since it uses less digits than its factorization.

78385655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15677136.

The product of its digits is 1008000, while the sum is 47.

The square root of 78385655 is about 8853.5673601097. The cubic root of 78385655 is about 427.9688869426.

The spelling of 78385655 in words is "seventy-eight million, three hundred eighty-five thousand, six hundred fifty-five".