20645130 has 64 divisors (see below), whose sum is σ = 54857088. Its totient is φ = 4930560.

The previous prime is 20645111. The next prime is 20645137. The reversal of 20645130 is 3154602.

20645130 = 2030² + 2031² + ... + 2034².

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20645097 and 20645106.

It is not an unprimeable number, because it can be changed into a prime (20645137) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23662 + ... + 24518.

It is an arithmetic number, because the mean of its divisors is an integer number (857142).

Almost surely, 2^20645130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20645130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27428544).

20645130 is an abundant number, since it is smaller than the sum of its proper divisors (34211958).

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

20645130 is a wasteful number, since it uses less digits than its factorization.

20645130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20645130 is about 4543.6912307066. The cubic root of 20645130 is about 274.3295181312.

Adding to 20645130 its reverse (3154602), we get a palindrome (23799732).

The spelling of 20645130 in words is "twenty million, six hundred forty-five thousand, one hundred thirty".