7138123640621 has 2 divisors, whose sum is σ = 7138123640622. Its totient is φ = 7138123640620.

The previous prime is 7138123640597. The next prime is 7138123640633. The reversal of 7138123640621 is 1260463218317.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7127351484100 + 10772156521 = 2669710^2 + 103789^2 .

It is a cyclic number.

It is not a de Polignac number, because 7138123640621 - 2³⁴ = 7120943771437 is a prime.

It is a super-2 number, since 2×7138123640621² (a number of 27 digits) contains 22 as substring.

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 (7138123640821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3569061820310 + 3569061820311.

It is an arithmetic number, because the mean of its divisors is an integer number (3569061820311).

Almost surely, 2^{7138123640621} is an apocalyptic number.

It is an amenable number.

7138123640621 is a deficient number, since it is larger than the sum of its proper divisors (1).

7138123640621 is an equidigital number, since it uses as much as digits as its factorization.

7138123640621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 44.

Adding to 7138123640621 its reverse (1260463218317), we get a palindrome (8398586858938).

The spelling of 7138123640621 in words is "seven trillion, one hundred thirty-eight billion, one hundred twenty-three million, six hundred forty thousand, six hundred twenty-one".