2121705 has 12 divisors (see below), whose sum is σ = 3677700. Its totient is φ = 1131552.

The previous prime is 2121683. The next prime is 2121737. The reversal of 2121705 is 5071212.

It can be written as a sum of positive squares in 2 ways, for example, as 242064 + 1879641 = 492^2 + 1371^2 .

It is not a de Polignac number, because 2121705 - 2⁹ = 2121193 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23530 + ... + 23619.

It is an arithmetic number, because the mean of its divisors is an integer number (306475).

2^2121705 is an apocalyptic number.

It is an amenable number.

2121705 is a deficient number, since it is larger than the sum of its proper divisors (1555995).

2121705 is a wasteful number, since it uses less digits than its factorization.

2121705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47160 (or 47157 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 2121705 is about 1456.6073595860. The cubic root of 2121705 is about 128.4975951747.

Adding to 2121705 its reverse (5071212), we get a palindrome (7192917).

The spelling of 2121705 in words is "two million, one hundred twenty-one thousand, seven hundred five".