91021686392541 has 4 divisors (see below), whose sum is σ = 121362248523392. Its totient is φ = 60681124261692.

The previous prime is 91021686392519. The next prime is 91021686392573. The reversal of 91021686392541 is 14529368612019.

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.

It is not a de Polignac number, because 91021686392541 - 2¹¹ = 91021686390493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91021686392141) 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, 15170281065421 + ... + 15170281065426.

It is an arithmetic number, because the mean of its divisors is an integer number (30340562130848).

Almost surely, 2^{91021686392541} is an apocalyptic number.

It is an amenable number.

91021686392541 is a deficient number, since it is larger than the sum of its proper divisors (30340562130851).

91021686392541 is a wasteful number, since it uses less digits than its factorization.

91021686392541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30340562130850.

The product of its (nonzero) digits is 5598720, while the sum is 57.

The spelling of 91021686392541 in words is "ninety-one trillion, twenty-one billion, six hundred eighty-six million, three hundred ninety-two thousand, five hundred forty-one".