20542431 has 32 divisors (see below), whose sum is σ = 34449408. Its totient is φ = 10598400.

The previous prime is 20542399. The next prime is 20542447. The reversal of 20542431 is 13424502.

It is not a de Polignac number, because 20542431 - 2⁵ = 20542399 is a prime.

It is a super-2 number, since 2×20542431² = 843982942779522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20542398 and 20542407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20542451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12031 + ... + 13631.

It is an arithmetic number, because the mean of its divisors is an integer number (1076544).

Almost surely, 2^20542431 is an apocalyptic number.

20542431 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20542431 is a deficient number, since it is larger than the sum of its proper divisors (13906977).

20542431 is a wasteful number, since it uses less digits than its factorization.

20542431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1671.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20542431 is about 4532.3758670260. The cubic root of 20542431 is about 273.8738785887.

Adding to 20542431 its reverse (13424502), we get a palindrome (33966933).

The spelling of 20542431 in words is "twenty million, five hundred forty-two thousand, four hundred thirty-one".