10991857 has 2 divisors, whose sum is σ = 10991858. Its totient is φ = 10991856.

The previous prime is 10991839. The next prime is 10991863. The reversal of 10991857 is 75819901.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9790641 + 1201216 = 3129^2 + 1096^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10991857 is a prime.

It is not a weakly prime, because it can be changed into another prime (10991807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5495928 + 5495929.

It is an arithmetic number, because the mean of its divisors is an integer number (5495929).

Almost surely, 2^10991857 is an apocalyptic number.

It is an amenable number.

10991857 is a deficient number, since it is larger than the sum of its proper divisors (1).

10991857 is an equidigital number, since it uses as much as digits as its factorization.

10991857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 10991857 is about 3315.3969596415. The cubic root of 10991857 is about 222.3431171161.

The spelling of 10991857 in words is "ten million, nine hundred ninety-one thousand, eight hundred fifty-seven".