20409550 has 24 divisors (see below), whose sum is σ = 43385616. Its totient is φ = 6997440.

The previous prime is 20409547. The next prime is 20409583. The reversal of 20409550 is 5590402.

It is a Harshad number since it is a multiple of its sum of digits (25).

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, 28807 + ... + 29506.

It is an arithmetic number, because the mean of its divisors is an integer number (1807734).

Almost surely, 2^20409550 is an apocalyptic number.

20409550 is an abundant number, since it is smaller than the sum of its proper divisors (22976066).

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

20409550 is a wasteful number, since it uses less digits than its factorization.

20409550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58332 (or 58327 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20409550 is about 4517.6929953241. The cubic root of 20409550 is about 273.2820728118.

Adding to 20409550 its reverse (5590402), we get a palindrome (25999952).

The spelling of 20409550 in words is "twenty million, four hundred nine thousand, five hundred fifty".