1601691091 has 64 divisors (see below), whose sum is σ = 2315851776. Its totient is φ = 1065830400.

The previous prime is 1601691073. The next prime is 1601691121. The reversal of 1601691091 is 1901961061.

It is a cyclic number.

It is not a de Polignac number, because 1601691091 - 2¹¹ = 1601689043 is a prime.

1601691091 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 (1601691011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1037266 + ... + 1038808.

It is an arithmetic number, because the mean of its divisors is an integer number (36185184).

Almost surely, 2^1601691091 is an apocalyptic number.

1601691091 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1601691091 is a deficient number, since it is larger than the sum of its proper divisors (714160685).

1601691091 is a wasteful number, since it uses less digits than its factorization.

1601691091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1652.

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

The square root of 1601691091 is about 40021.1330549249. The cubic root of 1601691091 is about 1170.0190152022.

The spelling of 1601691091 in words is "one billion, six hundred one million, six hundred ninety-one thousand, ninety-one".