140171921 has 2 divisors, whose sum is σ = 140171922. Its totient is φ = 140171920.

The previous prime is 140171917. The next prime is 140171923. The reversal of 140171921 is 129171041.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140161921 + 10000 = 11839^2 + 100^2 .

It is an emirp because it is prime and its reverse (129171041) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 140171921 - 2² = 140171917 is a prime.

Together with 140171923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (140171923) 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, 70085960 + 70085961.

It is an arithmetic number, because the mean of its divisors is an integer number (70085961).

Almost surely, 2^140171921 is an apocalyptic number.

It is an amenable number.

140171921 is a deficient number, since it is larger than the sum of its proper divisors (1).

140171921 is an equidigital number, since it uses as much as digits as its factorization.

140171921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 26.

The square root of 140171921 is about 11839.4223254346. The cubic root of 140171921 is about 519.4618705694.

The spelling of 140171921 in words is "one hundred forty million, one hundred seventy-one thousand, nine hundred twenty-one".