91242561 has 8 divisors (see below), whose sum is σ = 121736320. Its totient is φ = 60788592.

The previous prime is 91242559. The next prime is 91242563. The reversal of 91242561 is 16524219.

It is an interprime number because it is at equal distance from previous prime (91242559) and next prime (91242563).

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

It is not a de Polignac number, because 91242561 - 2¹ = 91242559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91242563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4105 + ... + 14118.

It is an arithmetic number, because the mean of its divisors is an integer number (15217040).

Almost surely, 2^91242561 is an apocalyptic number.

It is an amenable number.

91242561 is a deficient number, since it is larger than the sum of its proper divisors (30493759).

91242561 is a wasteful number, since it uses less digits than its factorization.

91242561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19895.

The product of its digits is 4320, while the sum is 30.

The square root of 91242561 is about 9552.0972042793. The cubic root of 91242561 is about 450.1934328902.

The spelling of 91242561 in words is "ninety-one million, two hundred forty-two thousand, five hundred sixty-one".