91705751621 has 8 divisors (see below), whose sum is σ = 101309001600. Its totient is φ = 82313562240.

The previous prime is 91705751617. The next prime is 91705751681. The reversal of 91705751621 is 12615750719.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91705751621 - 2² = 91705751617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91705751611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52764236 + ... + 52765973.

It is an arithmetic number, because the mean of its divisors is an integer number (12663625200).

Almost surely, 2^91705751621 is an apocalyptic number.

It is an amenable number.

91705751621 is a deficient number, since it is larger than the sum of its proper divisors (9603249979).

91705751621 is a wasteful number, since it uses less digits than its factorization.

91705751621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105530299.

The product of its (nonzero) digits is 132300, while the sum is 44.

The spelling of 91705751621 in words is "ninety-one billion, seven hundred five million, seven hundred fifty-one thousand, six hundred twenty-one".