20531286 has 32 divisors (see below), whose sum is σ = 48028800. Its totient is φ = 6483240.

The previous prime is 20531243. The next prime is 20531297. The reversal of 20531286 is 68213502.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8980 + ... + 11031.

It is an arithmetic number, because the mean of its divisors is an integer number (1500900).

Almost surely, 2^20531286 is an apocalyptic number.

20531286 is an abundant number, since it is smaller than the sum of its proper divisors (27497514).

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

20531286 is a wasteful number, since it uses less digits than its factorization.

20531286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20041 (or 20035 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 20531286 is about 4531.1462126045. The cubic root of 20531286 is about 273.8243408532.

Adding to 20531286 its reverse (68213502), we get a palindrome (88744788).

The spelling of 20531286 in words is "twenty million, five hundred thirty-one thousand, two hundred eighty-six".