20205431 has 8 divisors (see below), whose sum is σ = 21811680. Its totient is φ = 18659872.

The previous prime is 20205389. The next prime is 20205467. The reversal of 20205431 is 13450202.

20205431 = T₁₃₁₄ + T₁₃₁₅ + ... + T₁₃₃₆.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20205431 is a prime.

It is a super-2 number, since 2×20205431² = 816518883791522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20205481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14480 + ... + 15813.

It is an arithmetic number, because the mean of its divisors is an integer number (2726460).

Almost surely, 2^20205431 is an apocalyptic number.

20205431 is a deficient number, since it is larger than the sum of its proper divisors (1606249).

20205431 is a wasteful number, since it uses less digits than its factorization.

20205431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30345.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20205431 is about 4495.0451610635. The cubic root of 20205431 is about 272.3679735262.

Adding to 20205431 its reverse (13450202), we get a palindrome (33655633).

The spelling of 20205431 in words is "twenty million, two hundred five thousand, four hundred thirty-one".