891661293 has 6 divisors (see below), whose sum is σ = 1287955214. Its totient is φ = 594440856.

The previous prime is 891661213. The next prime is 891661297. The reversal of 891661293 is 392166198.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 891201609 + 459684 = 29853^2 + 678^2 .

It is not a de Polignac number, because 891661293 - 2⁸ = 891661037 is a prime.

It is a super-2 number, since 2×891661293² = 1590119722868863698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891661297) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 49536730 + ... + 49536747.

Almost surely, 2^891661293 is an apocalyptic number.

It is an amenable number.

891661293 is a deficient number, since it is larger than the sum of its proper divisors (396293921).

891661293 is a wasteful number, since it uses less digits than its factorization.

891661293 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99073483 (or 99073480 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 891661293 is about 29860.6981331649. The cubic root of 891661293 is about 962.4983007335.

The spelling of 891661293 in words is "eight hundred ninety-one million, six hundred sixty-one thousand, two hundred ninety-three".