20731542 has 32 divisors (see below), whose sum is σ = 45330432. Its totient is φ = 6282144.

The previous prime is 20731499. The next prime is 20731553. The reversal of 20731542 is 24513702.

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 15 ways as a sum of consecutive naturals, for example, 3243 + ... + 7209.

It is an arithmetic number, because the mean of its divisors is an integer number (1416576).

Almost surely, 2^20731542 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20731542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22665216).

20731542 is an abundant number, since it is smaller than the sum of its proper divisors (24598890).

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

20731542 is a wasteful number, since it uses less digits than its factorization.

20731542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4052.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20731542 is about 4553.1903101013. The cubic root of 20731542 is about 274.7117287767.

The spelling of 20731542 in words is "twenty million, seven hundred thirty-one thousand, five hundred forty-two".