20390550 has 24 divisors (see below), whose sum is σ = 50568936. Its totient is φ = 5437440.

The previous prime is 20390549. The next prime is 20390569. The reversal of 20390550 is 5509302.

It is a self number, because there is not a number n which added to its sum of digits gives 20390550.

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, 67819 + ... + 68118.

It is an arithmetic number, because the mean of its divisors is an integer number (2107039).

Almost surely, 2^20390550 is an apocalyptic number.

20390550 is an abundant number, since it is smaller than the sum of its proper divisors (30178386).

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

20390550 is a wasteful number, since it uses less digits than its factorization.

20390550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135952 (or 135947 counting only the distinct ones).

The product of its (nonzero) digits is 1350, while the sum is 24.

The square root of 20390550 is about 4515.5896624915. The cubic root of 20390550 is about 273.1972437086.

Adding to 20390550 its reverse (5509302), we get a palindrome (25899852).

The spelling of 20390550 in words is "twenty million, three hundred ninety thousand, five hundred fifty".