891632997 has 6 divisors (see below), whose sum is σ = 1287914342. Its totient is φ = 594421992.

The previous prime is 891632933. The next prime is 891632999. The reversal of 891632997 is 799236198.

It can be written as a sum of positive squares in only one way, i.e., 595311201 + 296321796 = 24399^2 + 17214^2 .

It is not a de Polignac number, because 891632997 - 2⁶ = 891632933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891632999) 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, 49535158 + ... + 49535175.

Almost surely, 2^891632997 is an apocalyptic number.

It is an amenable number.

891632997 is a deficient number, since it is larger than the sum of its proper divisors (396281345).

891632997 is a wasteful number, since it uses less digits than its factorization.

891632997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99070339 (or 99070336 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 54.

The square root of 891632997 is about 29860.2243293650. The cubic root of 891632997 is about 962.4881193114.

The spelling of 891632997 in words is "eight hundred ninety-one million, six hundred thirty-two thousand, nine hundred ninety-seven".