20051550 has 60 divisors (see below), whose sum is σ = 55724856. Its totient is φ = 5346000.

The previous prime is 20051539. The next prime is 20051587. The reversal of 20051550 is 5515002.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 1575 + ... + 6525.

Almost surely, 2^20051550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20051550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27862428).

20051550 is an abundant number, since it is smaller than the sum of its proper divisors (35673306).

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

20051550 is a wasteful number, since it uses less digits than its factorization.

20051550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4975 (or 4961 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 18.

The square root of 20051550 is about 4477.8957111572. The cubic root of 20051550 is about 271.6747752900.

Adding to 20051550 its reverse (5515002), we get a palindrome (25566552).

The spelling of 20051550 in words is "twenty million, fifty-one thousand, five hundred fifty".