997881089 has 4 divisors (see below), whose sum is σ = 1001131824. Its totient is φ = 994630356.

The previous prime is 997881047. The next prime is 997881119. The reversal of 997881089 is 980188799.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997881089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997886089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1624907 + ... + 1625520.

It is an arithmetic number, because the mean of its divisors is an integer number (250282956).

Almost surely, 2^997881089 is an apocalyptic number.

It is an amenable number.

997881089 is a deficient number, since it is larger than the sum of its proper divisors (3250735).

997881089 is a wasteful number, since it uses less digits than its factorization.

997881089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3250734.

The product of its (nonzero) digits is 2612736, while the sum is 59.

The square root of 997881089 is about 31589.2559108315. The cubic root of 997881089 is about 999.2931968804.

The spelling of 997881089 in words is "nine hundred ninety-seven million, eight hundred eighty-one thousand, eighty-nine".