1661881269 has 8 divisors (see below), whose sum is σ = 2221689760. Its totient is φ = 1104996816.

The previous prime is 1661881241. The next prime is 1661881271. The reversal of 1661881269 is 9621881661.

1661881269 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1661881269 - 2⁵ = 1661881237 is a prime.

It is a super-2 number, since 2×1661881269² = 5523698704506100722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661881289) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 729682 + ... + 731955.

It is an arithmetic number, because the mean of its divisors is an integer number (277711220).

Almost surely, 2^1661881269 is an apocalyptic number.

It is an amenable number.

1661881269 is a deficient number, since it is larger than the sum of its proper divisors (559808491).

1661881269 is a wasteful number, since it uses less digits than its factorization.

1661881269 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462019.

The product of its digits is 248832, while the sum is 48.

The square root of 1661881269 is about 40766.1780033400. The cubic root of 1661881269 is about 1184.4952704601.

The spelling of 1661881269 in words is "one billion, six hundred sixty-one million, eight hundred eighty-one thousand, two hundred sixty-nine".