1661344641 has 96 divisors (see below), whose sum is σ = 2824281600. Its totient is φ = 963705600.

The previous prime is 1661344613. The next prime is 1661344661. The reversal of 1661344641 is 1464431661.

1661344641 = 353³ + 354³ + ... + 385³.

1661344641 is a `hidden beast` number, since 1 + 6 + 6 + 1 + 3 + 4 + 4 + 641 = 666.

It is not a de Polignac number, because 1661344641 - 2¹⁰ = 1661343617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1661344596 and 1661344605.

It is not an unprimeable number, because it can be changed into a prime (1661344661) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10581735 + ... + 10581891.

It is an arithmetic number, because the mean of its divisors is an integer number (29419600).

Almost surely, 2^1661344641 is an apocalyptic number.

1661344641 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1661344641 is a deficient number, since it is larger than the sum of its proper divisors (1162936959).

1661344641 is a wasteful number, since it uses less digits than its factorization.

1661344641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 291 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 1661344641 is about 40759.5956923029. The cubic root of 1661344641 is about 1184.3677640074.

The spelling of 1661344641 in words is "one billion, six hundred sixty-one million, three hundred forty-four thousand, six hundred forty-one".