2181420247 has 2 divisors, whose sum is σ = 2181420248. Its totient is φ = 2181420246.

The previous prime is 2181420239. The next prime is 2181420271. The reversal of 2181420247 is 7420241812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2181420247 - 2³ = 2181420239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181420217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090710123 + 1090710124.

It is an arithmetic number, because the mean of its divisors is an integer number (1090710124).

Almost surely, 2^2181420247 is an apocalyptic number.

2181420247 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181420247 is an equidigital number, since it uses as much as digits as its factorization.

2181420247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 2181420247 is about 46705.6768177060. The cubic root of 2181420247 is about 1296.9197778951.

The spelling of 2181420247 in words is "two billion, one hundred eighty-one million, four hundred twenty thousand, two hundred forty-seven".