31405001209 has 2 divisors, whose sum is σ = 31405001210. Its totient is φ = 31405001208.

The previous prime is 31405001191. The next prime is 31405001293. The reversal of 31405001209 is 90210050413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30915485584 + 489515625 = 175828^2 + 22125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31405001209 is a prime.

It is not a weakly prime, because it can be changed into another prime (31405001809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15702500604 + 15702500605.

It is an arithmetic number, because the mean of its divisors is an integer number (15702500605).

Almost surely, 2^31405001209 is an apocalyptic number.

It is an amenable number.

31405001209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31405001209 is an equidigital number, since it uses as much as digits as its factorization.

31405001209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The spelling of 31405001209 in words is "thirty-one billion, four hundred five million, one thousand, two hundred nine".