18718501 has 2 divisors, whose sum is σ = 18718502. Its totient is φ = 18718500.

The previous prime is 18718493. The next prime is 18718507. The reversal of 18718501 is 10581781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18714276 + 4225 = 4326^2 + 65^2 .

It is a cyclic number.

It is not a de Polignac number, because 18718501 - 2³ = 18718493 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18718507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9359250 + 9359251.

It is an arithmetic number, because the mean of its divisors is an integer number (9359251).

Almost surely, 2^18718501 is an apocalyptic number.

It is an amenable number.

18718501 is a deficient number, since it is larger than the sum of its proper divisors (1).

18718501 is an equidigital number, since it uses as much as digits as its factorization.

18718501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 31.

The square root of 18718501 is about 4326.4882988401. The cubic root of 18718501 is about 265.5157914339.

The spelling of 18718501 in words is "eighteen million, seven hundred eighteen thousand, five hundred one".