2121745 has 8 divisors (see below), whose sum is σ = 2581416. Its totient is φ = 1673856.

The previous prime is 2121739. The next prime is 2121751. The reversal of 2121745 is 5471212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2121739) and next prime (2121751).

It can be written as a sum of positive squares in 4 ways, for example, as 410881 + 1710864 = 641^2 + 1308^2 .

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 2121745 - 2³ = 2121737 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2542 + ... + 3271.

It is an arithmetic number, because the mean of its divisors is an integer number (322677).

2^2121745 is an apocalyptic number.

It is an amenable number.

2121745 is a deficient number, since it is larger than the sum of its proper divisors (459671).

2121745 is an equidigital number, since it uses as much as digits as its factorization.

2121745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5891.

The product of its digits is 560, while the sum is 22.

The square root of 2121745 is about 1456.6210900574. The cubic root of 2121745 is about 128.4984026812.

Adding to 2121745 its reverse (5471212), we get a palindrome (7592957).

The spelling of 2121745 in words is "two million, one hundred twenty-one thousand, seven hundred forty-five".