6442519991 has 2 divisors, whose sum is σ = 6442519992. Its totient is φ = 6442519990.

The previous prime is 6442519987. The next prime is 6442519997. The reversal of 6442519991 is 1999152446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6442519991 - 2² = 6442519987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6442519997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3221259995 + 3221259996.

It is an arithmetic number, because the mean of its divisors is an integer number (3221259996).

Almost surely, 2^6442519991 is an apocalyptic number.

6442519991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6442519991 is an equidigital number, since it uses as much as digits as its factorization.

6442519991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 50.

The square root of 6442519991 is about 80265.3100099912. The cubic root of 6442519991 is about 1860.7381345027.

The spelling of 6442519991 in words is "six billion, four hundred forty-two million, five hundred nineteen thousand, nine hundred ninety-one".