16665330261 has 4 divisors (see below), whose sum is σ = 22220440352. Its totient is φ = 11110220172.

The previous prime is 16665330239. The next prime is 16665330263. The reversal of 16665330261 is 16203356661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16665330261 - 2⁹ = 16665329749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16665330263) 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, 2777555041 + ... + 2777555046.

It is an arithmetic number, because the mean of its divisors is an integer number (5555110088).

Almost surely, 2^16665330261 is an apocalyptic number.

It is an amenable number.

16665330261 is a deficient number, since it is larger than the sum of its proper divisors (5555110091).

16665330261 is an equidigital number, since it uses as much as digits as its factorization.

16665330261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5555110090.

The product of its (nonzero) digits is 116640, while the sum is 39.

The spelling of 16665330261 in words is "sixteen billion, six hundred sixty-five million, three hundred thirty thousand, two hundred sixty-one".