20540540 has 12 divisors (see below), whose sum is σ = 43135176. Its totient is φ = 8216208.

The previous prime is 20540537. The next prime is 20540543. The reversal of 20540540 is 4504502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20540537) and next prime (20540543).

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1027027 = 20540540 / (2 + 0 + 5 + 4 + 0 + 5 + 4 + 0).

20540540 is a modest number, since divided by 540540 gives 20 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20540543) 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, 513494 + ... + 513533.

It is an arithmetic number, because the mean of its divisors is an integer number (3594598).

Almost surely, 2^20540540 is an apocalyptic number.

20540540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20540540 is an abundant number, since it is smaller than the sum of its proper divisors (22594636).

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

20540540 is a wasteful number, since it uses less digits than its factorization.

20540540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027036 (or 1027034 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 20.

The square root of 20540540 is about 4532.1672519888. The cubic root of 20540540 is about 273.8654746597.

The spelling of 20540540 in words is "twenty million, five hundred forty thousand, five hundred forty".