140423021 has 2 divisors, whose sum is σ = 140423022. Its totient is φ = 140423020.

The previous prime is 140422999. The next prime is 140423039. The reversal of 140423021 is 120324041.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78234025 + 62188996 = 8845^2 + 7886^2 .

It is an emirp because it is prime and its reverse (120324041) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-140423021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (140423051) 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, 70211510 + 70211511.

It is an arithmetic number, because the mean of its divisors is an integer number (70211511).

Almost surely, 2^140423021 is an apocalyptic number.

It is an amenable number.

140423021 is a deficient number, since it is larger than the sum of its proper divisors (1).

140423021 is an equidigital number, since it uses as much as digits as its factorization.

140423021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 140423021 is about 11850.0219831020. The cubic root of 140423021 is about 519.7718686185.

Adding to 140423021 its reverse (120324041), we get a palindrome (260747062).

The spelling of 140423021 in words is "one hundred forty million, four hundred twenty-three thousand, twenty-one".