1991279158 has 8 divisors (see below), whose sum is σ = 3258456840. Its totient is φ = 905126880.

The previous prime is 1991279153. The next prime is 1991279159. The reversal of 1991279158 is 8519721991.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991279153) 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, 45256323 + ... + 45256366.

It is an arithmetic number, because the mean of its divisors is an integer number (407307105).

Almost surely, 2^1991279158 is an apocalyptic number.

1991279158 is a deficient number, since it is larger than the sum of its proper divisors (1267177682).

1991279158 is a wasteful number, since it uses less digits than its factorization.

1991279158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90512702.

The product of its digits is 408240, while the sum is 52.

The square root of 1991279158 is about 44623.7510525505. The cubic root of 1991279158 is about 1258.0871196689.

The spelling of 1991279158 in words is "one billion, nine hundred ninety-one million, two hundred seventy-nine thousand, one hundred fifty-eight".