6442420981 has 2 divisors, whose sum is σ = 6442420982. Its totient is φ = 6442420980.

The previous prime is 6442420921. The next prime is 6442420993. The reversal of 6442420981 is 1890242446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4521352081 + 1921068900 = 67241^2 + 43830^2 .

It is a cyclic number.

It is not a de Polignac number, because 6442420981 - 2²³ = 6434032373 is a prime.

It is a super-2 number, since 2×6442420981² = 83009576192858004722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6442420921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3221210490 + 3221210491.

It is an arithmetic number, because the mean of its divisors is an integer number (3221210491).

Almost surely, 2^6442420981 is an apocalyptic number.

It is an amenable number.

6442420981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6442420981 is an equidigital number, since it uses as much as digits as its factorization.

6442420981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 6442420981 is about 80264.6932405525. The cubic root of 6442420981 is about 1860.7286023824.

The spelling of 6442420981 in words is "six billion, four hundred forty-two million, four hundred twenty thousand, nine hundred eighty-one".