7946238721 has 2 divisors, whose sum is σ = 7946238722. Its totient is φ = 7946238720.

The previous prime is 7946238701. The next prime is 7946238799. The reversal of 7946238721 is 1278326497.

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., 5470081600 + 2476157121 = 73960^2 + 49761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7946238721 is a prime.

It is a super-2 number, since 2×7946238721² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7946238701) 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, 3973119360 + 3973119361.

It is an arithmetic number, because the mean of its divisors is an integer number (3973119361).

Almost surely, 2^7946238721 is an apocalyptic number.

It is an amenable number.

7946238721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7946238721 is an equidigital number, since it uses as much as digits as its factorization.

7946238721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1016064, while the sum is 49.

The square root of 7946238721 is about 89141.6778000055. The cubic root of 7946238721 is about 1995.5098201031.

The spelling of 7946238721 in words is "seven billion, nine hundred forty-six million, two hundred thirty-eight thousand, seven hundred twenty-one".