16801991261 has 16 divisors (see below), whose sum is σ = 19066320000. Its totient is φ = 14666299200.

The previous prime is 16801991231. The next prime is 16801991309. The reversal of 16801991261 is 16219910861.

It is a cyclic number.

It is not a de Polignac number, because 16801991261 - 2⁶ = 16801991197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16801991231) 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 15 ways as a sum of consecutive naturals, for example, 87761 + ... + 203238.

It is an arithmetic number, because the mean of its divisors is an integer number (1191645000).

Almost surely, 2^16801991261 is an apocalyptic number.

16801991261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16801991261 is a deficient number, since it is larger than the sum of its proper divisors (2264328739).

16801991261 is a wasteful number, since it uses less digits than its factorization.

16801991261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291220.

The product of its (nonzero) digits is 46656, while the sum is 44.

The spelling of 16801991261 in words is "sixteen billion, eight hundred one million, nine hundred ninety-one thousand, two hundred sixty-one".