2978418218221 has 2 divisors, whose sum is σ = 2978418218222. Its totient is φ = 2978418218220.

The previous prime is 2978418218201. The next prime is 2978418218231. The reversal of 2978418218221 is 1228128148792.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2933036437321 + 45381780900 = 1712611^2 + 213030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2978418218221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2978418218201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1489209109110 + 1489209109111.

It is an arithmetic number, because the mean of its divisors is an integer number (1489209109111).

Almost surely, 2^{2978418218221} is an apocalyptic number.

It is an amenable number.

2978418218221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2978418218221 is an equidigital number, since it uses as much as digits as its factorization.

2978418218221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2064384, while the sum is 55.

The spelling of 2978418218221 in words is "two trillion, nine hundred seventy-eight billion, four hundred eighteen million, two hundred eighteen thousand, two hundred twenty-one".