10991858 has 4 divisors (see below), whose sum is σ = 16487790. Its totient is φ = 5495928.

The previous prime is 10991857. The next prime is 10991863. The reversal of 10991858 is 85819901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85819901 = 71 ⋅1208731.

It can be written as a sum of positive squares in only one way, i.e., 10804369 + 187489 = 3287^2 + 433^2 .

It is not an unprimeable number, because it can be changed into a prime (10991857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2747963 + ... + 2747966.

Almost surely, 2^10991858 is an apocalyptic number.

10991858 is a deficient number, since it is larger than the sum of its proper divisors (5495932).

10991858 is an equidigital number, since it uses as much as digits as its factorization.

10991858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5495931.

The product of its (nonzero) digits is 25920, while the sum is 41.

The square root of 10991858 is about 3315.3971104530. The cubic root of 10991858 is about 222.3431238588.

The spelling of 10991858 in words is "ten million, nine hundred ninety-one thousand, eight hundred fifty-eight".