18440761 has 4 divisors (see below), whose sum is σ = 18482832. Its totient is φ = 18398692.

The previous prime is 18440743. The next prime is 18440791. The reversal of 18440761 is 16704481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16704481 = 1433 ⋅11657.

It is a cyclic number.

It is not a de Polignac number, because 18440761 - 2⁷ = 18440633 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18440731) 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 in 3 ways as a sum of consecutive naturals, for example, 20371 + ... + 21256.

It is an arithmetic number, because the mean of its divisors is an integer number (4620708).

Almost surely, 2^18440761 is an apocalyptic number.

It is an amenable number.

18440761 is a deficient number, since it is larger than the sum of its proper divisors (42071).

18440761 is an equidigital number, since it uses as much as digits as its factorization.

18440761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42070.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 18440761 is about 4294.2707180614. The cubic root of 18440761 is about 264.1960254013.

The spelling of 18440761 in words is "eighteen million, four hundred forty thousand, seven hundred sixty-one".