7215779 has 2 divisors, whose sum is σ = 7215780. Its totient is φ = 7215778.

The previous prime is 7215749. The next prime is 7215797. The reversal of 7215779 is 9775127.

Together with next prime (7215797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7215779 is a prime.

It is not a weakly prime, because it can be changed into another prime (7215709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3607889 + 3607890.

It is an arithmetic number, because the mean of its divisors is an integer number (3607890).

Almost surely, 2^7215779 is an apocalyptic number.

7215779 is a deficient number, since it is larger than the sum of its proper divisors (1).

7215779 is an equidigital number, since it uses as much as digits as its factorization.

7215779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30870, while the sum is 38.

The square root of 7215779 is about 2686.2202069078. The cubic root of 7215779 is about 193.2388337880.

It can be divided in two parts, 72 and 15779, that added together give a palindrome (15851).

The spelling of 7215779 in words is "seven million, two hundred fifteen thousand, seven hundred seventy-nine".