20015540 has 12 divisors (see below), whose sum is σ = 42032676. Its totient is φ = 8006208.

The previous prime is 20015537. The next prime is 20015551. The reversal of 20015540 is 4551002.

It can be written as a sum of positive squares in 2 ways, for example, as 12475024 + 7540516 = 3532^2 + 2746^2 .

20015540 is a modest number, since divided by 15540 gives 20 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 500369 + ... + 500408.

It is an arithmetic number, because the mean of its divisors is an integer number (3502723).

Almost surely, 2^20015540 is an apocalyptic number.

20015540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20015540 is an abundant number, since it is smaller than the sum of its proper divisors (22017136).

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

20015540 is a wasteful number, since it uses less digits than its factorization.

20015540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000786 (or 1000784 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 20015540 is about 4473.8730424544. The cubic root of 20015540 is about 271.5120468750.

Adding to 20015540 its reverse (4551002), we get a palindrome (24566542).

The spelling of 20015540 in words is "twenty million, fifteen thousand, five hundred forty".