18733428 has 72 divisors (see below), whose sum is σ = 54862080. Its totient is φ = 5279040.

The previous prime is 18733399. The next prime is 18733457. The reversal of 18733428 is 82433781.

It is an interprime number because it is at equal distance from previous prime (18733399) and next prime (18733457).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18733392 and 18733401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19438 + ... + 20378.

Almost surely, 2^18733428 is an apocalyptic number.

18733428 is a gapful number since it is divisible by the number (18) 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 18733428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27431040).

18733428 is an abundant number, since it is smaller than the sum of its proper divisors (36128652).

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

18733428 is a wasteful number, since it uses less digits than its factorization.

18733428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037 (or 1032 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 18733428 is about 4328.2130261807. The cubic root of 18733428 is about 265.5863508796.

The spelling of 18733428 in words is "eighteen million, seven hundred thirty-three thousand, four hundred twenty-eight".