91715546421 has 24 divisors (see below), whose sum is σ = 137073495000. Its totient is φ = 59023544832.

The previous prime is 91715546381. The next prime is 91715546423. The reversal of 91715546421 is 12464551719.

91715546421 is a `hidden beast` number, since 9 + 1 + 71 + 554 + 6 + 4 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4993542225 + 86722004196 = 70665^2 + 294486^2 .

It is not a de Polignac number, because 91715546421 - 2¹⁴ = 91715530037 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91715546423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1389945 + ... + 1454433.

It is an arithmetic number, because the mean of its divisors is an integer number (5711395625).

Almost surely, 2^91715546421 is an apocalyptic number.

It is an amenable number.

91715546421 is a deficient number, since it is larger than the sum of its proper divisors (45357948579).

91715546421 is a wasteful number, since it uses less digits than its factorization.

91715546421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69973 (or 69970 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The spelling of 91715546421 in words is "ninety-one billion, seven hundred fifteen million, five hundred forty-six thousand, four hundred twenty-one".