2391841647421 has 2 divisors, whose sum is σ = 2391841647422. Its totient is φ = 2391841647420.

The previous prime is 2391841647337. The next prime is 2391841647451. The reversal of 2391841647421 is 1247461481932.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1432497796900 + 959343850521 = 1196870^2 + 979461^2 .

It is a cyclic number.

It is not a de Polignac number, because 2391841647421 - 2⁴¹ = 192818391869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2391841647451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1195920823710 + 1195920823711.

It is an arithmetic number, because the mean of its divisors is an integer number (1195920823711).

Almost surely, 2^{2391841647421} is an apocalyptic number.

It is an amenable number.

2391841647421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2391841647421 is an equidigital number, since it uses as much as digits as its factorization.

2391841647421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 52.

The spelling of 2391841647421 in words is "two trillion, three hundred ninety-one billion, eight hundred forty-one million, six hundred forty-seven thousand, four hundred twenty-one".