18278401 has 2 divisors, whose sum is σ = 18278402. Its totient is φ = 18278400.

The previous prime is 18278371. The next prime is 18278419. The reversal of 18278401 is 10487281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17640000 + 638401 = 4200^2 + 799^2 .

It is a cyclic number.

It is not a de Polignac number, because 18278401 - 2⁵ = 18278369 is a prime.

It is not a weakly prime, because it can be changed into another prime (18278431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9139200 + 9139201.

It is an arithmetic number, because the mean of its divisors is an integer number (9139201).

Almost surely, 2^18278401 is an apocalyptic number.

It is an amenable number.

18278401 is a deficient number, since it is larger than the sum of its proper divisors (1).

18278401 is an equidigital number, since it uses as much as digits as its factorization.

18278401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 18278401 is about 4275.3246660341. The cubic root of 18278401 is about 263.4183753888.

The spelling of 18278401 in words is "eighteen million, two hundred seventy-eight thousand, four hundred one".