1991068858 has 8 divisors (see below), whose sum is σ = 2987460180. Its totient is φ = 995248800.

The previous prime is 1991068847. The next prime is 1991068873. The reversal of 1991068858 is 8588601991.

It can be written as a sum of positive squares in 2 ways, for example, as 1707920929 + 283147929 = 41327^2 + 16827^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 1991068799 and 1991068808.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133993 + ... + 148108.

Almost surely, 2^1991068858 is an apocalyptic number.

1991068858 is a deficient number, since it is larger than the sum of its proper divisors (996391322).

1991068858 is a wasteful number, since it uses less digits than its factorization.

1991068858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285632.

The product of its (nonzero) digits is 1244160, while the sum is 55.

The square root of 1991068858 is about 44621.3946218627. The cubic root of 1991068858 is about 1258.0428290372.

The spelling of 1991068858 in words is "one billion, nine hundred ninety-one million, sixty-eight thousand, eight hundred fifty-eight".