18915306551 has 2 divisors, whose sum is σ = 18915306552. Its totient is φ = 18915306550.

The previous prime is 18915306541. The next prime is 18915306577. The reversal of 18915306551 is 15560351981.

It is a weak prime.

It is an emirp because it is prime and its reverse (15560351981) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18915306551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18915306541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9457653275 + 9457653276.

It is an arithmetic number, because the mean of its divisors is an integer number (9457653276).

Almost surely, 2^18915306551 is an apocalyptic number.

18915306551 is a deficient number, since it is larger than the sum of its proper divisors (1).

18915306551 is an equidigital number, since it uses as much as digits as its factorization.

18915306551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162000, while the sum is 44.

The spelling of 18915306551 in words is "eighteen billion, nine hundred fifteen million, three hundred six thousand, five hundred fifty-one".