2158117649 has 4 divisors (see below), whose sum is σ = 2285065764. Its totient is φ = 2031169536.

The previous prime is 2158117631. The next prime is 2158117691. The reversal of 2158117649 is 9467118512.

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 1903140625 + 254977024 = 43625^2 + 15968^2 .

It is a cyclic number.

It is not a de Polignac number, because 2158117649 - 2²⁰ = 2157069073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2158117609) 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, 63474032 + ... + 63474065.

It is an arithmetic number, because the mean of its divisors is an integer number (571266441).

Almost surely, 2^2158117649 is an apocalyptic number.

It is an amenable number.

2158117649 is a deficient number, since it is larger than the sum of its proper divisors (126948115).

2158117649 is a wasteful number, since it uses less digits than its factorization.

2158117649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126948114.

The product of its digits is 120960, while the sum is 44.

The square root of 2158117649 is about 46455.5448681855. The cubic root of 2158117649 is about 1292.2852046763.

The spelling of 2158117649 in words is "two billion, one hundred fifty-eight million, one hundred seventeen thousand, six hundred forty-nine".