91701557144649 has 81 divisors (see below), whose sum is σ = 136113811204917. Its totient is φ = 59491899110592.

The previous prime is 91701557144647. The next prime is 91701557144777. The reversal of 91701557144649 is 94644175510719.

It is a happy number.

The square root of 91701557144649 is 9576093.

It is a perfect power (a square), and thus also a powerful number.

91701557144649 is a `hidden beast` number, since 9 + 1 + 7 + 0 + 1 + 557 + 14 + 4 + 64 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 42524549577225 + 49177007567424 = 6521085^2 + 7012632^2 .

It is not a de Polignac number, because 91701557144649 - 2¹ = 91701557144647 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91701557144647) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 348675122092 + ... + 348675122354.

Almost surely, 2^{91701557144649} is an apocalyptic number.

91701557144649 is the 9576093-rd square number.

91701557144649 is the 4788047-th centered octagonal number.

It is an amenable number.

91701557144649 is a deficient number, since it is larger than the sum of its proper divisors (44412254060268).

91701557144649 is an frugal number, since it uses more digits than its factorization.

91701557144649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1096 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 38102400, while the sum is 63.

The spelling of 91701557144649 in words is "ninety-one trillion, seven hundred one billion, five hundred fifty-seven million, one hundred forty-four thousand, six hundred forty-nine".