909897993 has 6 divisors (see below), whose sum is σ = 1314297114. Its totient is φ = 606598656.

The previous prime is 909897979. The next prime is 909898027. The reversal of 909897993 is 399798909.

It can be written as a sum of positive squares in only one way, i.e., 661929984 + 247968009 = 25728^2 + 15747^2 .

It is a de Polignac number, because none of the positive numbers 2^k-909897993 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 909897993.

It is not an unprimeable number, because it can be changed into a prime (909897913) 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, 50549880 + ... + 50549897.

It is an arithmetic number, because the mean of its divisors is an integer number (219049519).

Almost surely, 2^909897993 is an apocalyptic number.

It is an amenable number.

909897993 is a deficient number, since it is larger than the sum of its proper divisors (404399121).

909897993 is a wasteful number, since it uses less digits than its factorization.

909897993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101099783 (or 101099780 counting only the distinct ones).

The product of its (nonzero) digits is 9920232, while the sum is 63.

The square root of 909897993 is about 30164.5154610513. The cubic root of 909897993 is about 969.0158981631.

The spelling of 909897993 in words is "nine hundred nine million, eight hundred ninety-seven thousand, nine hundred ninety-three".