91781137 has 8 divisors (see below), whose sum is σ = 105911936. Its totient is φ = 77905152.

The previous prime is 91781117. The next prime is 91781141. The reversal of 91781137 is 73118719.

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 91781137 - 2⁷ = 91781009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91781096 and 91781105.

It is not an unprimeable number, because it can be changed into a prime (91781117) 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, 62928 + ... + 64369.

It is an arithmetic number, because the mean of its divisors is an integer number (13238992).

Almost surely, 2^91781137 is an apocalyptic number.

It is an amenable number.

91781137 is a deficient number, since it is larger than the sum of its proper divisors (14130799).

91781137 is a wasteful number, since it uses less digits than its factorization.

91781137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127407.

The product of its digits is 10584, while the sum is 37.

The square root of 91781137 is about 9580.2472306303. The cubic root of 91781137 is about 451.0774789332.

The spelling of 91781137 in words is "ninety-one million, seven hundred eighty-one thousand, one hundred thirty-seven".