91547405561 has 4 divisors (see below), whose sum is σ = 91548474192. Its totient is φ = 91546336932.

The previous prime is 91547405527. The next prime is 91547405629. The reversal of 91547405561 is 16550474519.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16550474519 = 127 ⋅130318697.

It is a cyclic number.

It is not a de Polignac number, because 91547405561 - 2⁶ = 91547405497 is a prime.

It is a super-3 number, since 3×91547405561³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91547405501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 393431 + ... + 581276.

It is an arithmetic number, because the mean of its divisors is an integer number (22887118548).

Almost surely, 2^91547405561 is an apocalyptic number.

It is an amenable number.

91547405561 is a deficient number, since it is larger than the sum of its proper divisors (1068631).

91547405561 is an equidigital number, since it uses as much as digits as its factorization.

91547405561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1068630.

The product of its (nonzero) digits is 756000, while the sum is 47.

The spelling of 91547405561 in words is "ninety-one billion, five hundred forty-seven million, four hundred five thousand, five hundred sixty-one".