18717978078 has 24 divisors (see below), whose sum is σ = 42941244528. Its totient is φ = 5872306752.

The previous prime is 18717978077. The next prime is 18717978127. The reversal of 18717978078 is 87087971781.

It is a super-3 number, since 3×18717978078³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18717978073) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30584626 + ... + 30585237.

It is an arithmetic number, because the mean of its divisors is an integer number (1789218522).

Almost surely, 2^18717978078 is an apocalyptic number.

18717978078 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18717978078 is an abundant number, since it is smaller than the sum of its proper divisors (24223266450).

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

18717978078 is a wasteful number, since it uses less digits than its factorization.

18717978078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61169888 (or 61169885 counting only the distinct ones).

The product of its (nonzero) digits is 11063808, while the sum is 63.

The spelling of 18717978078 in words is "eighteen billion, seven hundred seventeen million, nine hundred seventy-eight thousand, seventy-eight".