7040021 has 2 divisors, whose sum is σ = 7040022. Its totient is φ = 7040020.

The previous prime is 7040017. The next prime is 7040041. The reversal of 7040021 is 1200407.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6832996 + 207025 = 2614^2 + 455^2 .

It is a cyclic number.

It is not a de Polignac number, because 7040021 - 2² = 7040017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 7039978 and 7040005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7040041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3520010 + 3520011.

It is an arithmetic number, because the mean of its divisors is an integer number (3520011).

Almost surely, 2^7040021 is an apocalyptic number.

It is an amenable number.

7040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

7040021 is an equidigital number, since it uses as much as digits as its factorization.

7040021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 7040021 is about 2653.3037896178. The cubic root of 7040021 is about 191.6569848502.

Adding to 7040021 its reverse (1200407), we get a palindrome (8240428).

The spelling of 7040021 in words is "seven million, forty thousand, twenty-one".