891781749 has 12 divisors (see below), whose sum is σ = 1288922700. Its totient is φ = 594154944.

The previous prime is 891781729. The next prime is 891781757. The reversal of 891781749 is 947187198.

891781749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 209004849 + 682776900 = 14457^2 + 26130^2 .

It is not a de Polignac number, because 891781749 - 2⁵ = 891781717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 891781695 and 891781704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891781729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14664 + ... + 44705.

It is an arithmetic number, because the mean of its divisors is an integer number (107410225).

Almost surely, 2^891781749 is an apocalyptic number.

It is an amenable number.

891781749 is a deficient number, since it is larger than the sum of its proper divisors (397140951).

891781749 is a wasteful number, since it uses less digits than its factorization.

891781749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61044 (or 61041 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 54.

The square root of 891781749 is about 29862.7150306197. The cubic root of 891781749 is about 962.5416406115.

The spelling of 891781749 in words is "eight hundred ninety-one million, seven hundred eighty-one thousand, seven hundred forty-nine".