91678121 has 2 divisors, whose sum is σ = 91678122. Its totient is φ = 91678120.

The previous prime is 91678117. The next prime is 91678141. The reversal of 91678121 is 12187619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64000000 + 27678121 = 8000^2 + 5261^2 .

It is a cyclic number.

It is not a de Polignac number, because 91678121 - 2² = 91678117 is a prime.

It is not a weakly prime, because it can be changed into another prime (91678141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45839060 + 45839061.

It is an arithmetic number, because the mean of its divisors is an integer number (45839061).

Almost surely, 2^91678121 is an apocalyptic number.

It is an amenable number.

91678121 is a deficient number, since it is larger than the sum of its proper divisors (1).

91678121 is an equidigital number, since it uses as much as digits as its factorization.

91678121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 35.

The square root of 91678121 is about 9574.8692419270. The cubic root of 91678121 is about 450.9086512366.

The spelling of 91678121 in words is "ninety-one million, six hundred seventy-eight thousand, one hundred twenty-one".