73887818561 has 2 divisors, whose sum is σ = 73887818562. Its totient is φ = 73887818560.

The previous prime is 73887818531. The next prime is 73887818611. The reversal of 73887818561 is 16581878837.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52679430400 + 21208388161 = 229520^2 + 145631^2 .

It is an emirp because it is prime and its reverse (16581878837) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73887818561 - 2⁶ = 73887818497 is a prime.

It is a super-2 number, since 2×73887818561² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 73887818494 and 73887818503.

It is not a weakly prime, because it can be changed into another prime (73887818531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36943909280 + 36943909281.

It is an arithmetic number, because the mean of its divisors is an integer number (36943909281).

Almost surely, 2^73887818561 is an apocalyptic number.

It is an amenable number.

73887818561 is a deficient number, since it is larger than the sum of its proper divisors (1).

73887818561 is an equidigital number, since it uses as much as digits as its factorization.

73887818561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18063360, while the sum is 62.

The spelling of 73887818561 in words is "seventy-three billion, eight hundred eighty-seven million, eight hundred eighteen thousand, five hundred sixty-one".