2157556849 has 8 divisors (see below), whose sum is σ = 2490193728. Its totient is φ = 1831023600.

The previous prime is 2157556823. The next prime is 2157556859. The reversal of 2157556849 is 9486557512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2157556849 - 2⁷ = 2157556721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2157556796 and 2157556805.

It is not an unprimeable number, because it can be changed into a prime (2157556859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1525147 + ... + 1526560.

It is an arithmetic number, because the mean of its divisors is an integer number (311274216).

Almost surely, 2^2157556849 is an apocalyptic number.

It is an amenable number.

2157556849 is a deficient number, since it is larger than the sum of its proper divisors (332636879).

2157556849 is a wasteful number, since it uses less digits than its factorization.

2157556849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3051815.

The product of its digits is 3024000, while the sum is 52.

The square root of 2157556849 is about 46449.5085980465. The cubic root of 2157556849 is about 1292.1732589218.

The spelling of 2157556849 in words is "two billion, one hundred fifty-seven million, five hundred fifty-six thousand, eight hundred forty-nine".