20012431 has 4 divisors (see below), whose sum is σ = 20311192.
Its totient is φ = 19713672.
The previous prime is 20012423. The next prime is 20012441. The reversal of 20012431 is 13421002.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is not a de Polignac number, because 20012431 - 23 = 20012423 is a prime.
It is a super-2 number, since 2×200124312 = 800994789059522, 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 (20012401) 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, 149280 + ... + 149413.
It is an arithmetic number, because the mean of its divisors is an integer number (5077798).
Almost surely, 220012431 is an apocalyptic number.
20012431 is a deficient number, since it is larger than the sum of its proper divisors (298761).
20012431 is an equidigital number, since it uses as much as digits as its factorization.
20012431 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 298760.
The product of its (nonzero) digits is 48, while the sum is 13.
The square root of 20012431 is about 4473.5255671562.
The cubic root of 20012431 is about 271.4979882209.
Adding to 20012431 its reverse (13421002), we get a palindrome (33433433).
The spelling of 20012431 in words is "twenty million, twelve thousand, four hundred thirty-one".