18400749 has 16 divisors (see below), whose sum is σ = 26127360. Its totient is φ = 11479040.

The previous prime is 18400747. The next prime is 18400751. The reversal of 18400749 is 94700481.

It is an interprime number because it is at equal distance from previous prime (18400747) and next prime (18400751).

It is a cyclic number.

It is not a de Polignac number, because 18400749 - 2¹ = 18400747 is a prime.

It is a super-2 number, since 2×18400749² = 677175127522002, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18400741) 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, 8797 + ... + 10685.

It is an arithmetic number, because the mean of its divisors is an integer number (1632960).

Almost surely, 2^18400749 is an apocalyptic number.

It is an amenable number.

18400749 is a deficient number, since it is larger than the sum of its proper divisors (7726611).

18400749 is a wasteful number, since it uses less digits than its factorization.

18400749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2100.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 18400749 is about 4289.6094227797. The cubic root of 18400749 is about 264.0048065011.

The spelling of 18400749 in words is "eighteen million, four hundred thousand, seven hundred forty-nine".