6442517261 has 2 divisors, whose sum is σ = 6442517262. Its totient is φ = 6442517260.

The previous prime is 6442517239. The next prime is 6442517299. The reversal of 6442517261 is 1627152446.

It is a happy number.

It is an a-pointer prime, because the next prime (6442517299) can be obtained adding 6442517261 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5814062500 + 628454761 = 76250^2 + 25069^2 .

It is a cyclic number.

It is not a de Polignac number, because 6442517261 - 2⁶ = 6442517197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6442517231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3221258630 + 3221258631.

It is an arithmetic number, because the mean of its divisors is an integer number (3221258631).

Almost surely, 2^6442517261 is an apocalyptic number.

It is an amenable number.

6442517261 is a deficient number, since it is larger than the sum of its proper divisors (1).

6442517261 is an equidigital number, since it uses as much as digits as its factorization.

6442517261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 38.

The square root of 6442517261 is about 80265.2930038881. The cubic root of 6442517261 is about 1860.7378716751.

The spelling of 6442517261 in words is "six billion, four hundred forty-two million, five hundred seventeen thousand, two hundred sixty-one".