72644487709 has 2 divisors, whose sum is σ = 72644487710. Its totient is φ = 72644487708.

The previous prime is 72644487679. The next prime is 72644487719. The reversal of 72644487709 is 90778444627.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62801863609 + 9842624100 = 250603^2 + 99210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72644487709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72644487719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36322243854 + 36322243855.

It is an arithmetic number, because the mean of its divisors is an integer number (36322243855).

Almost surely, 2^72644487709 is an apocalyptic number.

It is an amenable number.

72644487709 is a deficient number, since it is larger than the sum of its proper divisors (1).

72644487709 is an equidigital number, since it uses as much as digits as its factorization.

72644487709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18966528, while the sum is 58.

The spelling of 72644487709 in words is "seventy-two billion, six hundred forty-four million, four hundred eighty-seven thousand, seven hundred nine".