31438945 has 4 divisors (see below), whose sum is σ = 37726740. Its totient is φ = 25151152.

The previous prime is 31438909. The next prime is 31438963. The reversal of 31438945 is 54983413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54983413 = 1237 ⋅44449.

It can be written as a sum of positive squares in 2 ways, for example, as 21307456 + 10131489 = 4616^2 + 3183^2 .

It is a cyclic number.

It is not a de Polignac number, because 31438945 - 2¹³ = 31430753 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3143890 + ... + 3143899.

It is an arithmetic number, because the mean of its divisors is an integer number (9431685).

Almost surely, 2^31438945 is an apocalyptic number.

It is an amenable number.

31438945 is a deficient number, since it is larger than the sum of its proper divisors (6287795).

31438945 is an equidigital number, since it uses as much as digits as its factorization.

31438945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6287794.

The product of its digits is 51840, while the sum is 37.

The square root of 31438945 is about 5607.0442302518. The cubic root of 31438945 is about 315.6138027593.

It can be divided in two parts, 31 and 438945, that added together give a cube (438976 = 76³).

The spelling of 31438945 in words is "thirty-one million, four hundred thirty-eight thousand, nine hundred forty-five".