9993781 has 16 divisors (see below), whose sum is σ = 11741184. Its totient is φ = 8330544.

The previous prime is 9993769. The next prime is 9993793. The reversal of 9993781 is 1873999.

9993781 = 63² + 64² + ... + 311².

It is an interprime number because it is at equal distance from previous prime (9993769) and next prime (9993793).

It is not a de Polignac number, because 9993781 - 2¹⁷ = 9862709 is a prime.

It is a super-2 number, since 2×9993781² = 199751317351922, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9993701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59760 + ... + 59926.

It is an arithmetic number, because the mean of its divisors is an integer number (733824).

Almost surely, 2^9993781 is an apocalyptic number.

It is an amenable number.

9993781 is a deficient number, since it is larger than the sum of its proper divisors (1747403).

9993781 is a wasteful number, since it uses less digits than its factorization.

9993781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360.

The product of its digits is 122472, while the sum is 46.

The square root of 9993781 is about 3161.2941970022. The cubic root of 9993781 is about 215.3987983105.

The spelling of 9993781 in words is "nine million, nine hundred ninety-three thousand, seven hundred eighty-one".