20408550 has 24 divisors (see below), whose sum is σ = 50613576. Its totient is φ = 5442240.

The previous prime is 20408543. The next prime is 20408561. The reversal of 20408550 is 5580402.

It is a self number, because there is not a number n which added to its sum of digits gives 20408550.

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, 67879 + ... + 68178.

It is an arithmetic number, because the mean of its divisors is an integer number (2108899).

Almost surely, 2^20408550 is an apocalyptic number.

20408550 is an abundant number, since it is smaller than the sum of its proper divisors (30205026).

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

20408550 is a wasteful number, since it uses less digits than its factorization.

20408550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136072 (or 136067 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 20408550 is about 4517.5823180104. The cubic root of 20408550 is about 273.2776094350.

Adding to 20408550 its reverse (5580402), we get a palindrome (25988952).

The spelling of 20408550 in words is "twenty million, four hundred eight thousand, five hundred fifty".