31044721 has 2 divisors, whose sum is σ = 31044722. Its totient is φ = 31044720.

The previous prime is 31044701. The next prime is 31044743. The reversal of 31044721 is 12744013.

It is an a-pointer prime, because the next prime (31044743) can be obtained adding 31044721 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27415696 + 3629025 = 5236^2 + 1905^2 .

It is a cyclic number.

It is not a de Polignac number, because 31044721 - 2⁷ = 31044593 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31044692 and 31044701.

It is not a weakly prime, because it can be changed into another prime (31044701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15522360 + 15522361.

It is an arithmetic number, because the mean of its divisors is an integer number (15522361).

Almost surely, 2^31044721 is an apocalyptic number.

It is an amenable number.

31044721 is a deficient number, since it is larger than the sum of its proper divisors (1).

31044721 is an equidigital number, since it uses as much as digits as its factorization.

31044721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 31044721 is about 5571.7789798232. The cubic root of 31044721 is about 314.2890525324.

Adding to 31044721 its reverse (12744013), we get a palindrome (43788734).

The spelling of 31044721 in words is "thirty-one million, forty-four thousand, seven hundred twenty-one".