140231209 has 2 divisors, whose sum is σ = 140231210. Its totient is φ = 140231208.

The previous prime is 140231173. The next prime is 140231243. The reversal of 140231209 is 902132041.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138579984 + 1651225 = 11772^2 + 1285^2 .

It is a cyclic number.

It is not a de Polignac number, because 140231209 - 2⁷ = 140231081 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 140231209.

It is not a weakly prime, because it can be changed into another prime (140241209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70115604 + 70115605.

It is an arithmetic number, because the mean of its divisors is an integer number (70115605).

Almost surely, 2^140231209 is an apocalyptic number.

It is an amenable number.

140231209 is a deficient number, since it is larger than the sum of its proper divisors (1).

140231209 is an equidigital number, since it uses as much as digits as its factorization.

140231209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 140231209 is about 11841.9258991095. The cubic root of 140231209 is about 519.5350985360.

The spelling of 140231209 in words is "one hundred forty million, two hundred thirty-one thousand, two hundred nine".