20215460 has 48 divisors (see below), whose sum is σ = 44135280. Its totient is φ = 7772160.

The previous prime is 20215457. The next prime is 20215463. The reversal of 20215460 is 6451202.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20215457) and next prime (20215463).

It can be written as a sum of positive squares in 8 ways, for example, as 8340544 + 11874916 = 2888^2 + 3446^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20215463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72842 + ... + 73118.

It is an arithmetic number, because the mean of its divisors is an integer number (919485).

Almost surely, 2^20215460 is an apocalyptic number.

20215460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20215460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22067640).

20215460 is an abundant number, since it is smaller than the sum of its proper divisors (23919820).

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

20215460 is a wasteful number, since it uses less digits than its factorization.

20215460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20215460 is about 4496.1605843208. The cubic root of 20215460 is about 272.4130295079.

Adding to 20215460 its reverse (6451202), we get a palindrome (26666662).

The spelling of 20215460 in words is "twenty million, two hundred fifteen thousand, four hundred sixty".