140404021 has 2 divisors, whose sum is σ = 140404022. Its totient is φ = 140404020.

The previous prime is 140404013. The next prime is 140404079. The reversal of 140404021 is 120404041.

140404021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137217796 + 3186225 = 11714^2 + 1785^2 .

It is a cyclic number.

It is not a de Polignac number, because 140404021 - 2³ = 140404013 is a prime.

It is a super-2 number, since 2×140404021² = 39426578225936882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 140403986 and 140404004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (140401021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70202010 + 70202011.

It is an arithmetic number, because the mean of its divisors is an integer number (70202011).

Almost surely, 2^140404021 is an apocalyptic number.

It is an amenable number.

140404021 is a deficient number, since it is larger than the sum of its proper divisors (1).

140404021 is an equidigital number, since it uses as much as digits as its factorization.

140404021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 140404021 is about 11849.2202697055. The cubic root of 140404021 is about 519.7484249057.

Adding to 140404021 its reverse (120404041), we get a palindrome (260808062).

The spelling of 140404021 in words is "one hundred forty million, four hundred four thousand, twenty-one".