212131009 has 2 divisors, whose sum is σ = 212131010. Its totient is φ = 212131008.

The previous prime is 212130983. The next prime is 212131013. The reversal of 212131009 is 900131212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181494784 + 30636225 = 13472^2 + 5535^2 .

It is a cyclic number.

It is not a de Polignac number, because 212131009 - 2¹³ = 212122817 is a prime.

It is not a weakly prime, because it can be changed into another prime (212131039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106065504 + 106065505.

It is an arithmetic number, because the mean of its divisors is an integer number (106065505).

Almost surely, 2^212131009 is an apocalyptic number.

It is an amenable number.

212131009 is a deficient number, since it is larger than the sum of its proper divisors (1).

212131009 is an equidigital number, since it uses as much as digits as its factorization.

212131009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 212131009 is about 14564.7179512684. The cubic root of 212131009 is about 596.3959961979.

It can be divided in two parts, 21213 and 1009, that added together give a palindrome (22222).

The spelling of 212131009 in words is "two hundred twelve million, one hundred thirty-one thousand, nine".