20431481 has 8 divisors (see below), whose sum is σ = 23827200. Its totient is φ = 17512404.

The previous prime is 20431451. The next prime is 20431547. The reversal of 20431481 is 18413402.

It is a de Polignac number, because none of the positive numbers 2^k-20431481 is a prime.

It is a super-2 number, since 2×20431481² = 834890831706722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20431421) 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, 29441 + ... + 30126.

It is an arithmetic number, because the mean of its divisors is an integer number (2978400).

Almost surely, 2^20431481 is an apocalyptic number.

It is an amenable number.

20431481 is a deficient number, since it is larger than the sum of its proper divisors (3395719).

20431481 is an frugal number, since it uses more digits than its factorization.

20431481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59588 (or 59574 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 20431481 is about 4520.1195780643. The cubic root of 20431481 is about 273.3799224901.

Adding to 20431481 its reverse (18413402), we get a palindrome (38844883).

The spelling of 20431481 in words is "twenty million, four hundred thirty-one thousand, four hundred eighty-one".