91891477 has 4 divisors (see below), whose sum is σ = 97296876. Its totient is φ = 86486080.

The previous prime is 91891447. The next prime is 91891483. The reversal of 91891477 is 77419819.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 71470116 + 20421361 = 8454^2 + 4519^2 .

It is a cyclic number.

It is not a de Polignac number, because 91891477 - 2¹⁹ = 91367189 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 (91891447) 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, 2702674 + ... + 2702707.

It is an arithmetic number, because the mean of its divisors is an integer number (24324219).

Almost surely, 2^91891477 is an apocalyptic number.

It is an amenable number.

91891477 is a deficient number, since it is larger than the sum of its proper divisors (5405399).

91891477 is a wasteful number, since it uses less digits than its factorization.

91891477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5405398.

The product of its digits is 127008, while the sum is 46.

The square root of 91891477 is about 9586.0042249104. The cubic root of 91891477 is about 451.2581694999.

The spelling of 91891477 in words is "ninety-one million, eight hundred ninety-one thousand, four hundred seventy-seven".