2115665551 has 2 divisors, whose sum is σ = 2115665552. Its totient is φ = 2115665550.

The previous prime is 2115665537. The next prime is 2115665569. The reversal of 2115665551 is 1555665112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2115665551 - 2¹⁹ = 2115141263 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2115665551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2115663551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1057832775 + 1057832776.

It is an arithmetic number, because the mean of its divisors is an integer number (1057832776).

Almost surely, 2^2115665551 is an apocalyptic number.

2115665551 is a deficient number, since it is larger than the sum of its proper divisors (1).

2115665551 is an equidigital number, since it uses as much as digits as its factorization.

2115665551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45000, while the sum is 37.

The square root of 2115665551 is about 45996.3645411243. The cubic root of 2115665551 is about 1283.7555618754.

The spelling of 2115665551 in words is "two billion, one hundred fifteen million, six hundred sixty-five thousand, five hundred fifty-one".