909871997 has 4 divisors (see below), whose sum is σ = 910536060. Its totient is φ = 909207936.

The previous prime is 909871957. The next prime is 909871999. The reversal of 909871997 is 799178909.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 806219236 + 103652761 = 28394^2 + 10181^2 .

It is a cyclic number.

It is not a de Polignac number, because 909871997 - 2⁸ = 909871741 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 (909871999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 329972 + ... + 332717.

It is an arithmetic number, because the mean of its divisors is an integer number (227634015).

Almost surely, 2^909871997 is an apocalyptic number.

It is an amenable number.

909871997 is a deficient number, since it is larger than the sum of its proper divisors (664063).

909871997 is a wasteful number, since it uses less digits than its factorization.

909871997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664062.

The product of its (nonzero) digits is 2571912, while the sum is 59.

The square root of 909871997 is about 30164.0845543172. The cubic root of 909871997 is about 969.0066697377.

The spelling of 909871997 in words is "nine hundred nine million, eight hundred seventy-one thousand, nine hundred ninety-seven".