1661835869 has 4 divisors (see below), whose sum is σ = 1685242080. Its totient is φ = 1638429660.

The previous prime is 1661835841. The next prime is 1661835881. The reversal of 1661835869 is 9685381661.

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 a cyclic number.

It is not a de Polignac number, because 1661835869 - 2¹⁶ = 1661770333 is a prime.

It is a super-2 number, since 2×1661835869² = 5523396910989970322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661835869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661835839) 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, 11702999 + ... + 11703140.

It is an arithmetic number, because the mean of its divisors is an integer number (421310520).

Almost surely, 2^1661835869 is an apocalyptic number.

It is an amenable number.

1661835869 is a deficient number, since it is larger than the sum of its proper divisors (23406211).

1661835869 is an equidigital number, since it uses as much as digits as its factorization.

1661835869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23406210.

The product of its digits is 1866240, while the sum is 53.

The square root of 1661835869 is about 40765.6211653889. The cubic root of 1661835869 is about 1184.4844841751.

The spelling of 1661835869 in words is "one billion, six hundred sixty-one million, eight hundred thirty-five thousand, eight hundred sixty-nine".