20251530 has 96 divisors (see below), whose sum is σ = 59754240. Its totient is φ = 4717440.

The previous prime is 20251529. The next prime is 20251531. The reversal of 20251530 is 3515202.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20251529) and next prime (20251531).

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

It is not an unprimeable number, because it can be changed into a prime (20251531) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21775 + ... + 22685.

It is an arithmetic number, because the mean of its divisors is an integer number (622440).

Almost surely, 2^20251530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20251530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29877120).

20251530 is an abundant number, since it is smaller than the sum of its proper divisors (39502710).

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

20251530 is a wasteful number, since it uses less digits than its factorization.

20251530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956 (or 953 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20251530 is about 4500.1699967890. The cubic root of 20251530 is about 272.5749534297.

Adding to 20251530 its reverse (3515202), we get a palindrome (23766732).

The spelling of 20251530 in words is "twenty million, two hundred fifty-one thousand, five hundred thirty".