20415400 has 24 divisors (see below), whose sum is σ = 47466270. Its totient is φ = 8166080.

The previous prime is 20415397. The next prime is 20415401. The reversal of 20415400 is 451402.

It can be written as a sum of positive squares in 3 ways, for example, as 18301284 + 2114116 = 4278^2 + 1454^2 .

It is not an unprimeable number, because it can be changed into a prime (20415401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50839 + ... + 51238.

Almost surely, 2^20415400 is an apocalyptic number.

20415400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20415400 is an abundant number, since it is smaller than the sum of its proper divisors (27050870).

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

20415400 is a wasteful number, since it uses less digits than its factorization.

20415400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102093 (or 102084 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 20415400 is about 4518.3404032897. The cubic root of 20415400 is about 273.3081806453.

Adding to 20415400 its reverse (451402), we get a palindrome (20866802).

The spelling of 20415400 in words is "twenty million, four hundred fifteen thousand, four hundred".