2115409861 has 2 divisors, whose sum is σ = 2115409862. Its totient is φ = 2115409860.

The previous prime is 2115409847. The next prime is 2115409867. The reversal of 2115409861 is 1689045112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2106259236 + 9150625 = 45894^2 + 3025^2 .

It is a cyclic number.

It is not a de Polignac number, because 2115409861 - 2²¹ = 2113312709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2115409861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2115409867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1057704930 + 1057704931.

It is an arithmetic number, because the mean of its divisors is an integer number (1057704931).

Almost surely, 2^2115409861 is an apocalyptic number.

It is an amenable number.

2115409861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2115409861 is an equidigital number, since it uses as much as digits as its factorization.

2115409861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 2115409861 is about 45993.5849983451. The cubic root of 2115409861 is about 1283.7038434482.

The spelling of 2115409861 in words is "two billion, one hundred fifteen million, four hundred nine thousand, eight hundred sixty-one".