31366421 has 4 divisors (see below), whose sum is σ = 31796172. Its totient is φ = 30936672.

The previous prime is 31366403. The next prime is 31366453. The reversal of 31366421 is 12466313.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5499025 + 25867396 = 2345^2 + 5086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31366421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31366481) 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, 214766 + ... + 214911.

It is an arithmetic number, because the mean of its divisors is an integer number (7949043).

Almost surely, 2^31366421 is an apocalyptic number.

It is an amenable number.

31366421 is a deficient number, since it is larger than the sum of its proper divisors (429751).

31366421 is an equidigital number, since it uses as much as digits as its factorization.

31366421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429750.

The product of its digits is 2592, while the sum is 26.

The square root of 31366421 is about 5600.5732742283. The cubic root of 31366421 is about 315.3709277865.

The spelling of 31366421 in words is "thirty-one million, three hundred sixty-six thousand, four hundred twenty-one".