31243421 has 8 divisors (see below), whose sum is σ = 34190688. Its totient is φ = 28314000.

The previous prime is 31243417. The next prime is 31243423. The reversal of 31243421 is 12434213.

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

It is not a de Polignac number, because 31243421 - 2² = 31243417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31243393 and 31243402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31243423) 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, 650 + ... + 7931.

It is an arithmetic number, because the mean of its divisors is an integer number (4273836).

Almost surely, 2^31243421 is an apocalyptic number.

It is an amenable number.

31243421 is a deficient number, since it is larger than the sum of its proper divisors (2947267).

31243421 is a wasteful number, since it uses less digits than its factorization.

31243421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8923.

The product of its digits is 576, while the sum is 20.

The square root of 31243421 is about 5589.5814691263. The cubic root of 31243421 is about 314.9581568675.

Adding to 31243421 its reverse (12434213), we get a palindrome (43677634).

The spelling of 31243421 in words is "thirty-one million, two hundred forty-three thousand, four hundred twenty-one".