20405542 has 32 divisors (see below), whose sum is σ = 33592320. Its totient is φ = 9260160.

The previous prime is 20405527. The next prime is 20405549. The reversal of 20405542 is 24550402.

It is a super-2 number, since 2×20405542² = 832772288627528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20405549) 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, 190653 + ... + 190759.

It is an arithmetic number, because the mean of its divisors is an integer number (1049760).

Almost surely, 2^20405542 is an apocalyptic number.

20405542 is a deficient number, since it is larger than the sum of its proper divisors (13186778).

20405542 is a wasteful number, since it uses less digits than its factorization.

20405542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276.

The product of its (nonzero) digits is 1600, while the sum is 22.

The square root of 20405542 is about 4517.2493843046. The cubic root of 20405542 is about 273.2641827186.

Adding to 20405542 its reverse (24550402), we get a palindrome (44955944).

The spelling of 20405542 in words is "twenty million, four hundred five thousand, five hundred forty-two".