1091691601 has 32 divisors (see below), whose sum is σ = 1552013568. Its totient is φ = 739031040.

The previous prime is 1091691589. The next prime is 1091691647. The reversal of 1091691601 is 1061961901.

It is not a de Polignac number, because 1091691601 - 2⁷ = 1091691473 is a prime.

1091691601 is a strobogrammatic number because it is the same when read upside-down.

It is not an unprimeable number, because it can be changed into a prime (1091691301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15060 + ... + 49093.

It is an arithmetic number, because the mean of its divisors is an integer number (48500424).

Almost surely, 2^1091691601 is an apocalyptic number.

1091691601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1091691601 is a deficient number, since it is larger than the sum of its proper divisors (460321967).

1091691601 is a wasteful number, since it uses less digits than its factorization.

1091691601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64201.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1091691601 is about 33040.7566650644. The cubic root of 1091691601 is about 1029.6745762408.

The spelling of 1091691601 in words is "one billion, ninety-one million, six hundred ninety-one thousand, six hundred one".