15571217551 has 2 divisors, whose sum is σ = 15571217552. Its totient is φ = 15571217550.

The previous prime is 15571217549. The next prime is 15571217567.

15571217551 is nontrivially palindromic in base 10.

It is a weak prime.

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 15571217551 - 2¹ = 15571217549 is a prime.

Together with 15571217549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15571217591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7785608775 + 7785608776.

It is an arithmetic number, because the mean of its divisors is an integer number (7785608776).

Almost surely, 2^15571217551 is an apocalyptic number.

15571217551 is a deficient number, since it is larger than the sum of its proper divisors (1).

15571217551 is an equidigital number, since it uses as much as digits as its factorization.

15571217551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61250, while the sum is 40.

The spelling of 15571217551 in words is "fifteen billion, five hundred seventy-one million, two hundred seventeen thousand, five hundred fifty-one".