721281066887 has 2 divisors, whose sum is σ = 721281066888. Its totient is φ = 721281066886.

The previous prime is 721281066871. The next prime is 721281066991. The reversal of 721281066887 is 788660182127.

It is a weak prime.

It is an emirp because it is prime and its reverse (788660182127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721281066887 - 2⁴ = 721281066871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721281066817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360640533443 + 360640533444.

It is an arithmetic number, because the mean of its divisors is an integer number (360640533444).

Almost surely, 2^721281066887 is an apocalyptic number.

721281066887 is a deficient number, since it is larger than the sum of its proper divisors (1).

721281066887 is an equidigital number, since it uses as much as digits as its factorization.

721281066887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3612672, while the sum is 56.

The spelling of 721281066887 in words is "seven hundred twenty-one billion, two hundred eighty-one million, sixty-six thousand, eight hundred eighty-seven".