1661384793 has 4 divisors (see below), whose sum is σ = 2215179728. Its totient is φ = 1107589860.

The previous prime is 1661384761. The next prime is 1661384801. The reversal of 1661384793 is 3974831661.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3974831661 = 3 ⋅1324943887.

It is not a de Polignac number, because 1661384793 - 2⁵ = 1661384761 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1661384713) 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, 276897463 + ... + 276897468.

It is an arithmetic number, because the mean of its divisors is an integer number (553794932).

Almost surely, 2^1661384793 is an apocalyptic number.

It is an amenable number.

1661384793 is a deficient number, since it is larger than the sum of its proper divisors (553794935).

1661384793 is an equidigital number, since it uses as much as digits as its factorization.

1661384793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553794934.

The product of its digits is 653184, while the sum is 48.

The square root of 1661384793 is about 40760.0882359202. The cubic root of 1661384793 is about 1184.3773053452.

The spelling of 1661384793 in words is "one billion, six hundred sixty-one million, three hundred eighty-four thousand, seven hundred ninety-three".