20001431 has 4 divisors (see below), whose sum is σ = 20016600. Its totient is φ = 19986264.

The previous prime is 20001389. The next prime is 20001439. The reversal of 20001431 is 13410002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13410002 = 2 ⋅6705001.

It is a cyclic number.

It is not a de Polignac number, because 20001431 - 2¹⁸ = 19739287 is a prime.

It is a super-2 number, since 2×20001431² = 800114484095522, 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 (20001439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5396 + ... + 8313.

It is an arithmetic number, because the mean of its divisors is an integer number (5004150).

Almost surely, 2^20001431 is an apocalyptic number.

20001431 is a deficient number, since it is larger than the sum of its proper divisors (15169).

20001431 is a wasteful number, since it uses less digits than its factorization.

20001431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15168.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20001431 is about 4472.2959428016. The cubic root of 20001431 is about 271.4482353911.

Adding to 20001431 its reverse (13410002), we get a palindrome (33411433).

The spelling of 20001431 in words is "twenty million, one thousand, four hundred thirty-one".