18813530 has 16 divisors (see below), whose sum is σ = 33985224. Its totient is φ = 7498560.

The previous prime is 18813481. The next prime is 18813539. The reversal of 18813530 is 3531881.

It can be written as a sum of positive squares in 4 ways, for example, as 17131321 + 1682209 = 4139^2 + 1297^2 .

It is a super-2 number, since 2×18813530² = 707897822121800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18813493 and 18813502.

It is not an unprimeable number, because it can be changed into a prime (18813539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 281 + ... + 6140.

Almost surely, 2^18813530 is an apocalyptic number.

18813530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18813530 is a deficient number, since it is larger than the sum of its proper divisors (15171694).

18813530 is a wasteful number, since it uses less digits than its factorization.

18813530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6721.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 18813530 is about 4337.4566280252. The cubic root of 18813530 is about 265.9643516024.

It can be divided in two parts, 188 and 13530, that multiplied together give a triangular number (2543640 = T₂₂₅₅).

The spelling of 18813530 in words is "eighteen million, eight hundred thirteen thousand, five hundred thirty".