31338561 has 4 divisors (see below), whose sum is σ = 41784752. Its totient is φ = 20892372.

The previous prime is 31338547. The next prime is 31338569. The reversal of 31338561 is 16583313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 31338561 - 2¹⁵ = 31305793 is a prime.

It is a super-3 number, since 3×31338561³ (a number of 23 digits) contains 333 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 (31338569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5223091 + ... + 5223096.

It is an arithmetic number, because the mean of its divisors is an integer number (10446188).

Almost surely, 2^31338561 is an apocalyptic number.

It is an amenable number.

31338561 is a deficient number, since it is larger than the sum of its proper divisors (10446191).

31338561 is a wasteful number, since it uses less digits than its factorization.

31338561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10446190.

The product of its digits is 6480, while the sum is 30.

The square root of 31338561 is about 5598.0854763035. The cubic root of 31338561 is about 315.2775281530.

The spelling of 31338561 in words is "thirty-one million, three hundred thirty-eight thousand, five hundred sixty-one".