993905641 has 16 divisors (see below), whose sum is σ = 1036215936. Its totient is φ = 952560000.

The previous prime is 993905623. The next prime is 993905807. The reversal of 993905641 is 146509399.

It is a 4-Lehmer number, since φ(993905641) divides (993905641-1)⁴.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 993905641 - 2¹⁷ = 993774569 is a prime.

It is a deceptive number, since it divides R_993905640.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 993905591 and 993905600.

It is not an unprimeable number, because it can be changed into a prime (993905041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1225126 + ... + 1225936.

It is an arithmetic number, because the mean of its divisors is an integer number (64763496).

It is a Poulet number, since it divides 2^993905640-1.

Almost surely, 2^993905641 is an apocalyptic number.

It is an amenable number.

993905641 is a deficient number, since it is larger than the sum of its proper divisors (42310295).

993905641 is a wasteful number, since it uses less digits than its factorization.

993905641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344.

The product of its (nonzero) digits is 262440, while the sum is 46.

The square root of 993905641 is about 31526.2690624818. The cubic root of 993905641 is about 997.9644061693.

The spelling of 993905641 in words is "nine hundred ninety-three million, nine hundred five thousand, six hundred forty-one".