2157889993 has 4 divisors (see below), whose sum is σ = 2466160000. Its totient is φ = 1849619988.

The previous prime is 2157889973. The next prime is 2157889997. The reversal of 2157889993 is 3999887512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2157889993 - 2¹³ = 2157881801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2157889997) 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, 154134993 + ... + 154135006.

It is an arithmetic number, because the mean of its divisors is an integer number (616540000).

Almost surely, 2^2157889993 is an apocalyptic number.

It is an amenable number.

2157889993 is a deficient number, since it is larger than the sum of its proper divisors (308270007).

2157889993 is an equidigital number, since it uses as much as digits as its factorization.

2157889993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308270006.

The product of its digits is 9797760, while the sum is 61.

The square root of 2157889993 is about 46453.0945470805. The cubic root of 2157889993 is about 1292.2397627876.

The spelling of 2157889993 in words is "two billion, one hundred fifty-seven million, eight hundred eighty-nine thousand, nine hundred ninety-three".