91281394 has 4 divisors (see below), whose sum is σ = 136922094. Its totient is φ = 45640696.

The previous prime is 91281373. The next prime is 91281397. The reversal of 91281394 is 49318219.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49318219 = 137 ⋅359987.

It can be written as a sum of positive squares in only one way, i.e., 52056225 + 39225169 = 7215^2 + 6263^2 .

It is not an unprimeable number, because it can be changed into a prime (91281397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22820347 + ... + 22820350.

Almost surely, 2^91281394 is an apocalyptic number.

91281394 is a deficient number, since it is larger than the sum of its proper divisors (45640700).

91281394 is a wasteful number, since it uses less digits than its factorization.

91281394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45640699.

The product of its digits is 15552, while the sum is 37.

The square root of 91281394 is about 9554.1296830219. The cubic root of 91281394 is about 450.2572915463.

The spelling of 91281394 in words is "ninety-one million, two hundred eighty-one thousand, three hundred ninety-four".