8913781 has 4 divisors (see below), whose sum is σ = 9154732. Its totient is φ = 8672832.

The previous prime is 8913767. The next prime is 8913787. The reversal of 8913781 is 1873198.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1873198 = 2 ⋅936599.

It can be written as a sum of positive squares in 2 ways, for example, as 5564881 + 3348900 = 2359^2 + 1830^2 .

It is a cyclic number.

It is not a de Polignac number, because 8913781 - 2²¹ = 6816629 is a prime.

It is a super-2 number, since 2×8913781² = 158910983431922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 240913 = 8913781 / (8 + 9 + 1 + 3 + 7 + 8 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8913781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8913787) 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, 120420 + ... + 120493.

It is an arithmetic number, because the mean of its divisors is an integer number (2288683).

Almost surely, 2^8913781 is an apocalyptic number.

It is an amenable number.

8913781 is a deficient number, since it is larger than the sum of its proper divisors (240951).

8913781 is a wasteful number, since it uses less digits than its factorization.

8913781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240950.

The product of its digits is 12096, while the sum is 37.

The square root of 8913781 is about 2985.5955854737. The cubic root of 8913781 is about 207.3420174561.

The spelling of 8913781 in words is "eight million, nine hundred thirteen thousand, seven hundred eighty-one".