2157838861 has 8 divisors (see below), whose sum is σ = 2171996064. Its totient is φ = 2143701360.

The previous prime is 2157838831. The next prime is 2157838867. The reversal of 2157838861 is 1688387512.

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

It is a cyclic number.

It is not a de Polignac number, because 2157838861 - 2⁵ = 2157838829 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 (2157838867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260790 + ... + 268936.

It is an arithmetic number, because the mean of its divisors is an integer number (271499508).

Almost surely, 2^2157838861 is an apocalyptic number.

It is an amenable number.

2157838861 is a deficient number, since it is larger than the sum of its proper divisors (14157203).

2157838861 is a wasteful number, since it uses less digits than its factorization.

2157838861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9851.

The product of its digits is 645120, while the sum is 49.

The square root of 2157838861 is about 46452.5441822081. The cubic root of 2157838861 is about 1292.2295560076.

The spelling of 2157838861 in words is "two billion, one hundred fifty-seven million, eight hundred thirty-eight thousand, eight hundred sixty-one".