2121729 has 8 divisors (see below), whose sum is σ = 2863392. Its totient is φ = 1397280.

The previous prime is 2121683. The next prime is 2121737. The reversal of 2121729 is 9271212.

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

It is not a de Polignac number, because 2121729 - 2⁷ = 2121601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121699 and 2121708.

It is not an unprimeable number, because it can be changed into a prime (2121739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4012 + ... + 4509.

It is an arithmetic number, because the mean of its divisors is an integer number (357924).

It is a Proth number, since it is equal to 259 ⋅ 2¹³ + 1 and 259 < 2¹³.

2^2121729 is an apocalyptic number.

It is an amenable number.

2121729 is a deficient number, since it is larger than the sum of its proper divisors (741663).

2121729 is an equidigital number, since it uses as much as digits as its factorization.

2121729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8607.

The product of its digits is 504, while the sum is 24.

The square root of 2121729 is about 1456.6155978844. The cubic root of 2121729 is about 128.4980796798.

It can be divided in two parts, 2121 and 729, that added together give a triangular number (2850 = T₇₅).

The spelling of 2121729 in words is "two million, one hundred twenty-one thousand, seven hundred twenty-nine".