91788061 has 4 divisors (see below), whose sum is σ = 91813824. Its totient is φ = 91762300.

The previous prime is 91788041. The next prime is 91788079. The reversal of 91788061 is 16088719.

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 a cyclic number.

It is not a de Polignac number, because 91788061 - 2⁵ = 91788029 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 (91788001) 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, 6475 + ... + 15016.

It is an arithmetic number, because the mean of its divisors is an integer number (22953456).

Almost surely, 2^91788061 is an apocalyptic number.

It is an amenable number.

91788061 is a deficient number, since it is larger than the sum of its proper divisors (25763).

91788061 is a wasteful number, since it uses less digits than its factorization.

91788061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25762.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 91788061 is about 9580.6085923599. The cubic root of 91788061 is about 451.0888217938.

The spelling of 91788061 in words is "ninety-one million, seven hundred eighty-eight thousand, sixty-one".