18278997 has 16 divisors (see below), whose sum is σ = 27744768. Its totient is φ = 10596080.

The previous prime is 18278987. The next prime is 18279013. The reversal of 18278997 is 79987281.

It is not a de Polignac number, because 18278997 - 2¹⁸ = 18016853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18278947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11283 + ... + 12800.

It is an arithmetic number, because the mean of its divisors is an integer number (1734048).

Almost surely, 2^18278997 is an apocalyptic number.

It is an amenable number.

18278997 is a deficient number, since it is larger than the sum of its proper divisors (9465771).

18278997 is a wasteful number, since it uses less digits than its factorization.

18278997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24120.

The product of its digits is 508032, while the sum is 51.

The square root of 18278997 is about 4275.3943677747. The cubic root of 18278997 is about 263.4212384337.

The spelling of 18278997 in words is "eighteen million, two hundred seventy-eight thousand, nine hundred ninety-seven".