915455777881 has 2 divisors, whose sum is σ = 915455777882. Its totient is φ = 915455777880.

The previous prime is 915455777861. The next prime is 915455777897. The reversal of 915455777881 is 188777554519.

915455777881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 688966401600 + 226489376281 = 830040^2 + 475909^2 .

It is an emirp because it is prime and its reverse (188777554519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 915455777881 - 2¹⁹ = 915455253593 is a prime.

It is a super-2 number, since 2×915455777881² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (915455777801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 457727888940 + 457727888941.

It is an arithmetic number, because the mean of its divisors is an integer number (457727888941).

Almost surely, 2^915455777881 is an apocalyptic number.

It is an amenable number.

915455777881 is a deficient number, since it is larger than the sum of its proper divisors (1).

915455777881 is an equidigital number, since it uses as much as digits as its factorization.

915455777881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98784000, while the sum is 67.

The spelling of 915455777881 in words is "nine hundred fifteen billion, four hundred fifty-five million, seven hundred seventy-seven thousand, eight hundred eighty-one".