7939220981 has 2 divisors, whose sum is σ = 7939220982. Its totient is φ = 7939220980.

The previous prime is 7939220941. The next prime is 7939220987. The reversal of 7939220981 is 1890229397.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7895211025 + 44009956 = 88855^2 + 6634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7939220981 is a prime.

It is a super-2 number, since 2×7939220981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7939220987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3969610490 + 3969610491.

It is an arithmetic number, because the mean of its divisors is an integer number (3969610491).

Almost surely, 2^7939220981 is an apocalyptic number.

It is an amenable number.

7939220981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7939220981 is an equidigital number, since it uses as much as digits as its factorization.

7939220981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 7939220981 is about 89102.3062608370. The cubic root of 7939220981 is about 1994.9222006373.

The spelling of 7939220981 in words is "seven billion, nine hundred thirty-nine million, two hundred twenty thousand, nine hundred eighty-one".