2156705 has 8 divisors (see below), whose sum is σ = 2740392. Its totient is φ = 1623808.

The previous prime is 2156699. The next prime is 2156711. The reversal of 2156705 is 5076512.

It is an interprime number because it is at equal distance from previous prime (2156699) and next prime (2156711).

It can be written as a sum of positive squares in 4 ways, for example, as 33856 + 2122849 = 184^2 + 1457^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2156705 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12602 + ... + 12771.

It is an arithmetic number, because the mean of its divisors is an integer number (342549).

2^2156705 is an apocalyptic number.

It is an amenable number.

2156705 is a deficient number, since it is larger than the sum of its proper divisors (583687).

2156705 is a wasteful number, since it uses less digits than its factorization.

2156705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25395.

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 2156705 is about 1468.5724360753. The cubic root of 2156705 is about 129.2003177440.

The spelling of 2156705 in words is "two million, one hundred fifty-six thousand, seven hundred five".