20505030 has 192 divisors, whose sum is σ = 65499840. Its totient is φ = 4064256.

The previous prime is 20505007. The next prime is 20505031. The reversal of 20505030 is 3050502.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505031) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 554172 + ... + 554208.

It is an arithmetic number, because the mean of its divisors is an integer number (341145).

Almost surely, 2^20505030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20505030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32749920).

20505030 is an abundant number, since it is smaller than the sum of its proper divisors (44994810).

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

20505030 is a wasteful number, since it uses less digits than its factorization.

20505030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 15.

The square root of 20505030 is about 4528.2480055757. The cubic root of 20505030 is about 273.7075662423.

Adding to 20505030 its reverse (3050502), we get a palindrome (23555532).

The spelling of 20505030 in words is "twenty million, five hundred five thousand, thirty".