18819540 has 60 divisors (see below), whose sum is σ = 59042676. Its totient is φ = 5018112.

The previous prime is 18819529. The next prime is 18819547. The reversal of 18819540 is 4591881.

It can be written as a sum of positive squares in 2 ways, for example, as 6625476 + 12194064 = 2574^2 + 3492^2 .

It is a tau number, because it is divible by the number of its divisors (60).

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 = 18819495 and 18819504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18819547) 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 19 ways as a sum of consecutive naturals, for example, 4189 + ... + 7428.

Almost surely, 2^18819540 is an apocalyptic number.

18819540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18819540 is an abundant number, since it is smaller than the sum of its proper divisors (40223136).

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

18819540 is a wasteful number, since it uses less digits than its factorization.

18819540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11638 (or 11627 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 18819540 is about 4338.1493750216. The cubic root of 18819540 is about 265.9926694420.

The spelling of 18819540 in words is "eighteen million, eight hundred nineteen thousand, five hundred forty".