2165273657 has 4 divisors (see below), whose sum is σ = 2169578880. Its totient is φ = 2160968436.

The previous prime is 2165273651. The next prime is 2165273699. The reversal of 2165273657 is 7563725612.

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 2165273657 - 2²² = 2161079353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2165273651) 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, 2151857 + ... + 2152862.

It is an arithmetic number, because the mean of its divisors is an integer number (542394720).

Almost surely, 2^2165273657 is an apocalyptic number.

It is an amenable number.

2165273657 is a deficient number, since it is larger than the sum of its proper divisors (4305223).

2165273657 is an equidigital number, since it uses as much as digits as its factorization.

2165273657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4305222.

The product of its digits is 529200, while the sum is 44.

The square root of 2165273657 is about 46532.5010825767. The cubic root of 2165273657 is about 1293.7119728622.

The spelling of 2165273657 in words is "two billion, one hundred sixty-five million, two hundred seventy-three thousand, six hundred fifty-seven".