18072820 has 12 divisors (see below), whose sum is σ = 37952964. Its totient is φ = 7229120.

The previous prime is 18072811. The next prime is 18072823. The reversal of 18072820 is 2827081.

It can be written as a sum of positive squares in 2 ways, for example, as 3602404 + 14470416 = 1898^2 + 3804^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18072823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451801 + ... + 451840.

It is an arithmetic number, because the mean of its divisors is an integer number (3162747).

Almost surely, 2^18072820 is an apocalyptic number.

18072820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18072820 is an abundant number, since it is smaller than the sum of its proper divisors (19880144).

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

18072820 is a wasteful number, since it uses less digits than its factorization.

18072820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903650 (or 903648 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 18072820 is about 4251.2139442752. The cubic root of 18072820 is about 262.4270757370.

The spelling of 18072820 in words is "eighteen million, seventy-two thousand, eight hundred twenty".