997847139 has 4 divisors (see below), whose sum is σ = 1330462856. Its totient is φ = 665231424.

The previous prime is 997847107. The next prime is 997847141. The reversal of 997847139 is 931748799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 931748799 = 3 ⋅310582933.

It is not a de Polignac number, because 997847139 - 2⁵ = 997847107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997847159) 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, 166307854 + ... + 166307859.

It is an arithmetic number, because the mean of its divisors is an integer number (332615714).

Almost surely, 2^997847139 is an apocalyptic number.

997847139 is a deficient number, since it is larger than the sum of its proper divisors (332615717).

997847139 is a wasteful number, since it uses less digits than its factorization.

997847139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332615716.

The product of its digits is 3429216, while the sum is 57.

The square root of 997847139 is about 31588.7185400105. The cubic root of 997847139 is about 999.2818640709.

The spelling of 997847139 in words is "nine hundred ninety-seven million, eight hundred forty-seven thousand, one hundred thirty-nine".