15368277721 has 2 divisors, whose sum is σ = 15368277722. Its totient is φ = 15368277720.

The previous prime is 15368277689. The next prime is 15368277779. The reversal of 15368277721 is 12777286351.

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., 14704957696 + 663320025 = 121264^2 + 25755^2 .

It is a cyclic number.

It is not a de Polignac number, because 15368277721 - 2⁵ = 15368277689 is a prime.

It is not a weakly prime, because it can be changed into another prime (15368274721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7684138860 + 7684138861.

It is an arithmetic number, because the mean of its divisors is an integer number (7684138861).

Almost surely, 2^15368277721 is an apocalyptic number.

It is an amenable number.

15368277721 is a deficient number, since it is larger than the sum of its proper divisors (1).

15368277721 is an equidigital number, since it uses as much as digits as its factorization.

15368277721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 987840, while the sum is 49.

The spelling of 15368277721 in words is "fifteen billion, three hundred sixty-eight million, two hundred seventy-seven thousand, seven hundred twenty-one".