31012221209 has 4 divisors (see below), whose sum is σ = 31520618340. Its totient is φ = 30503824080.

The previous prime is 31012221193. The next prime is 31012221269. The reversal of 31012221209 is 90212221013.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13172611984 + 17839609225 = 114772^2 + 133565^2 .

It is a cyclic number.

It is not a de Polignac number, because 31012221209 - 2⁴ = 31012221193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31012221269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254198474 + ... + 254198595.

It is an arithmetic number, because the mean of its divisors is an integer number (7880154585).

Almost surely, 2^31012221209 is an apocalyptic number.

It is an amenable number.

31012221209 is a deficient number, since it is larger than the sum of its proper divisors (508397131).

31012221209 is an equidigital number, since it uses as much as digits as its factorization.

31012221209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508397130.

The product of its (nonzero) digits is 432, while the sum is 23.

The spelling of 31012221209 in words is "thirty-one billion, twelve million, two hundred twenty-one thousand, two hundred nine".