20215481 has 16 divisors (see below), whose sum is σ = 23876160. Its totient is φ = 16873920.

The previous prime is 20215463. The next prime is 20215513. The reversal of 20215481 is 18451202.

It is a cyclic number.

It is not a de Polignac number, because 20215481 - 2⁶ = 20215417 is a prime.

It is a super-2 number, since 2×20215481² = 817331344122722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20215451) 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, 53150 + ... + 53528.

It is an arithmetic number, because the mean of its divisors is an integer number (1492260).

Almost surely, 2^20215481 is an apocalyptic number.

It is an amenable number.

20215481 is a deficient number, since it is larger than the sum of its proper divisors (3660679).

20215481 is a wasteful number, since it uses less digits than its factorization.

20215481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 20215481 is about 4496.1629196460. The cubic root of 20215481 is about 272.4131238363.

Adding to 20215481 its reverse (18451202), we get a palindrome (38666683).

The spelling of 20215481 in words is "twenty million, two hundred fifteen thousand, four hundred eighty-one".