72990719981 has 2 divisors, whose sum is σ = 72990719982. Its totient is φ = 72990719980.

The previous prime is 72990719969. The next prime is 72990720043. The reversal of 72990719981 is 18991709927.

It is an a-pointer prime, because the next prime (72990720043) can be obtained adding 72990719981 to its sum of digits (62).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60057344356 + 12933375625 = 245066^2 + 113725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72990719981 is a prime.

It is a super-2 number, since 2×72990719981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72990719911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36495359990 + 36495359991.

It is an arithmetic number, because the mean of its divisors is an integer number (36495359991).

Almost surely, 2^72990719981 is an apocalyptic number.

It is an amenable number.

72990719981 is a deficient number, since it is larger than the sum of its proper divisors (1).

72990719981 is an equidigital number, since it uses as much as digits as its factorization.

72990719981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5143824, while the sum is 62.

The spelling of 72990719981 in words is "seventy-two billion, nine hundred ninety million, seven hundred nineteen thousand, nine hundred eighty-one".