15621602497 has 2 divisors, whose sum is σ = 15621602498. Its totient is φ = 15621602496.

The previous prime is 15621602459. The next prime is 15621602509. The reversal of 15621602497 is 79420612651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14708595841 + 913006656 = 121279^2 + 30216^2 .

It is an emirp because it is prime and its reverse (79420612651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15621602497 - 2²⁷ = 15487384769 is a prime.

It is not a weakly prime, because it can be changed into another prime (15621602417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7810801248 + 7810801249.

It is an arithmetic number, because the mean of its divisors is an integer number (7810801249).

Almost surely, 2^15621602497 is an apocalyptic number.

It is an amenable number.

15621602497 is a deficient number, since it is larger than the sum of its proper divisors (1).

15621602497 is an equidigital number, since it uses as much as digits as its factorization.

15621602497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 15621602497 in words is "fifteen billion, six hundred twenty-one million, six hundred two thousand, four hundred ninety-seven".