78155455187 has 4 divisors (see below), whose sum is σ = 81553518480. Its totient is φ = 74757391896.

The previous prime is 78155455127. The next prime is 78155455207.

78155455187 is nontrivially palindromic in base 10.

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 78155455187 - 2³⁴ = 60975586003 is a prime.

It is a super-2 number, since 2×78155455187² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78155455127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1699031612 + ... + 1699031657.

It is an arithmetic number, because the mean of its divisors is an integer number (20388379620).

Almost surely, 2^78155455187 is an apocalyptic number.

78155455187 is a deficient number, since it is larger than the sum of its proper divisors (3398063293).

78155455187 is a wasteful number, since it uses less digits than its factorization.

78155455187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3398063292.

The product of its digits is 7840000, while the sum is 56.

The spelling of 78155455187 in words is "seventy-eight billion, one hundred fifty-five million, four hundred fifty-five thousand, one hundred eighty-seven".