1018957691 has 4 divisors (see below), whose sum is σ = 1023527232. Its totient is φ = 1014388152.

The previous prime is 1018957663. The next prime is 1018957711. The reversal of 1018957691 is 1967598101.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1018957691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1018957591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2284436 + ... + 2284881.

It is an arithmetic number, because the mean of its divisors is an integer number (255881808).

Almost surely, 2^1018957691 is an apocalyptic number.

1018957691 is a deficient number, since it is larger than the sum of its proper divisors (4569541).

1018957691 is an equidigital number, since it uses as much as digits as its factorization.

1018957691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4569540.

The product of its (nonzero) digits is 136080, while the sum is 47.

The square root of 1018957691 is about 31921.1166941258. The cubic root of 1018957691 is about 1006.2797129917.

The spelling of 1018957691 in words is "one billion, eighteen million, nine hundred fifty-seven thousand, six hundred ninety-one".