17918994387 has 48 divisors (see below), whose sum is σ = 28880369664. Its totient is φ = 9843120000.

The previous prime is 17918994361. The next prime is 17918994407. The reversal of 17918994387 is 78349981971.

It is a happy number.

It is not a de Polignac number, because 17918994387 - 2¹⁰ = 17918993363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (17918994337) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 675087 + ... + 701127.

It is an arithmetic number, because the mean of its divisors is an integer number (601674368).

Almost surely, 2^17918994387 is an apocalyptic number.

17918994387 is a deficient number, since it is larger than the sum of its proper divisors (10961375277).

17918994387 is a wasteful number, since it uses less digits than its factorization.

17918994387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26240 (or 26233 counting only the distinct ones).

The product of its digits is 27433728, while the sum is 66.

The spelling of 17918994387 in words is "seventeen billion, nine hundred eighteen million, nine hundred ninety-four thousand, three hundred eighty-seven".