20540400 has 60 divisors (see below), whose sum is σ = 65801592. Its totient is φ = 5477120.

The previous prime is 20540393. The next prime is 20540413. The reversal of 20540400 is 404502.

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 (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20540400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7359 + ... + 9758.

Almost surely, 2^20540400 is an apocalyptic number.

20540400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20540400 is an abundant number, since it is smaller than the sum of its proper divisors (45261192).

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

20540400 is a wasteful number, since it uses less digits than its factorization.

20540400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17138 (or 17127 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 15.

The square root of 20540400 is about 4532.1518068132. The cubic root of 20540400 is about 273.8648524551.

Adding to 20540400 its reverse (404502), we get a palindrome (20944902).

The spelling of 20540400 in words is "twenty million, five hundred forty thousand, four hundred".