40018261 has 2 divisors, whose sum is σ = 40018262. Its totient is φ = 40018260.

The previous prime is 40018259. The next prime is 40018283. The reversal of 40018261 is 16281004.

It is an a-pointer prime, because the next prime (40018283) can be obtained adding 40018261 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29095236 + 10923025 = 5394^2 + 3305^2 .

It is a cyclic number.

It is not a de Polignac number, because 40018261 - 2¹ = 40018259 is a prime.

It is a super-2 number, since 2×40018261² = 3202922426928242, which contains 22 as substring.

Together with 40018259, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40018211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20009130 + 20009131.

It is an arithmetic number, because the mean of its divisors is an integer number (20009131).

Almost surely, 2^40018261 is an apocalyptic number.

It is an amenable number.

40018261 is a deficient number, since it is larger than the sum of its proper divisors (1).

40018261 is an equidigital number, since it uses as much as digits as its factorization.

40018261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 40018261 is about 6325.9988144166. The cubic root of 40018261 is about 342.0472245356.

Adding to 40018261 its reverse (16281004), we get a palindrome (56299265).

The spelling of 40018261 in words is "forty million, eighteen thousand, two hundred sixty-one".