7216621727257 has 2 divisors, whose sum is σ = 7216621727258. Its totient is φ = 7216621727256.

The previous prime is 7216621727179. The next prime is 7216621727299. The reversal of 7216621727257 is 7527271266127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6984624408336 + 231997318921 = 2642844^2 + 481661^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7216621727257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7216621727198 and 7216621727207.

It is not a weakly prime, because it can be changed into another prime (7216661727257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3608310863628 + 3608310863629.

It is an arithmetic number, because the mean of its divisors is an integer number (3608310863629).

Almost surely, 2^{7216621727257} is an apocalyptic number.

It is an amenable number.

7216621727257 is a deficient number, since it is larger than the sum of its proper divisors (1).

7216621727257 is an equidigital number, since it uses as much as digits as its factorization.

7216621727257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6914880, while the sum is 55.

The spelling of 7216621727257 in words is "seven trillion, two hundred sixteen billion, six hundred twenty-one million, seven hundred twenty-seven thousand, two hundred fifty-seven".