2978126591 has 4 divisors (see below), whose sum is σ = 3248865384. Its totient is φ = 2707387800.

The previous prime is 2978126581. The next prime is 2978126597. The reversal of 2978126591 is 1956218792.

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

It is a cyclic number.

It is not a de Polignac number, because 2978126591 - 2¹⁸ = 2977864447 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 (2978126597) 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, 135369380 + ... + 135369401.

It is an arithmetic number, because the mean of its divisors is an integer number (812216346).

Almost surely, 2^2978126591 is an apocalyptic number.

2978126591 is a deficient number, since it is larger than the sum of its proper divisors (270738793).

2978126591 is a wasteful number, since it uses less digits than its factorization.

2978126591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270738792.

The product of its digits is 544320, while the sum is 50.

The square root of 2978126591 is about 54572.2144593748. The cubic root of 2978126591 is about 1438.7358038889.

It can be divided in two parts, 297812 and 6591, that added together give a palindrome (304403).

The spelling of 2978126591 in words is "two billion, nine hundred seventy-eight million, one hundred twenty-six thousand, five hundred ninety-one".