31450021 has 2 divisors, whose sum is σ = 31450022. Its totient is φ = 31450020.

The previous prime is 31449991. The next prime is 31450031. The reversal of 31450021 is 12005413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27185796 + 4264225 = 5214^2 + 2065^2 .

It is a cyclic number.

It is not a de Polignac number, because 31450021 - 2⁵ = 31449989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31449977 and 31450004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31450031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15725010 + 15725011.

It is an arithmetic number, because the mean of its divisors is an integer number (15725011).

Almost surely, 2^31450021 is an apocalyptic number.

It is an amenable number.

31450021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31450021 is an equidigital number, since it uses as much as digits as its factorization.

31450021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 31450021 is about 5608.0318294389. The cubic root of 31450021 is about 315.6508621882.

Adding to 31450021 its reverse (12005413), we get a palindrome (43455434).

The spelling of 31450021 in words is "thirty-one million, four hundred fifty thousand, twenty-one".