18121740 has 96 divisors (see below), whose sum is σ = 62469120. Its totient is φ = 3822336.

The previous prime is 18121721. The next prime is 18121759. The reversal of 18121740 is 4712181.

It is an interprime number because it is at equal distance from previous prime (18121721) and next prime (18121759).

It is a self number, because there is not a number n which added to its sum of digits gives 18121740.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3801 + ... + 7119.

It is an arithmetic number, because the mean of its divisors is an integer number (650720).

Almost surely, 2^18121740 is an apocalyptic number.

18121740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18121740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31234560).

18121740 is an abundant number, since it is smaller than the sum of its proper divisors (44347380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18121740 is a wasteful number, since it uses less digits than its factorization.

18121740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3351 (or 3349 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 18121740 is about 4256.9637066811. The cubic root of 18121740 is about 262.6636439939.

The spelling of 18121740 in words is "eighteen million, one hundred twenty-one thousand, seven hundred forty".