20215280 has 20 divisors (see below), whose sum is σ = 47000712. Its totient is φ = 8086080.

The previous prime is 20215267. The next prime is 20215301. The reversal of 20215280 is 8251202.

It is a tau number, because it is divible by the number of its divisors (20).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126266 + ... + 126425.

Almost surely, 2^20215280 is an apocalyptic number.

20215280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20215280 is an abundant number, since it is smaller than the sum of its proper divisors (26785432).

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

20215280 is a wasteful number, since it uses less digits than its factorization.

20215280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252704 (or 252698 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 20215280 is about 4496.1405671976. The cubic root of 20215280 is about 272.4122209767.

Adding to 20215280 its reverse (8251202), we get a palindrome (28466482).

The spelling of 20215280 in words is "twenty million, two hundred fifteen thousand, two hundred eighty".