2121739 has 2 divisors, whose sum is σ = 2121740. Its totient is φ = 2121738.

The previous prime is 2121737. The next prime is 2121751. The reversal of 2121739 is 9371212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121739 - 2¹ = 2121737 is a prime.

Together with 2121737, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2121737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060869 + 1060870.

It is an arithmetic number, because the mean of its divisors is an integer number (1060870).

2^2121739 is an apocalyptic number.

2121739 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121739 is an equidigital number, since it uses as much as digits as its factorization.

2121739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 25.

The square root of 2121739 is about 1456.6190304949. The cubic root of 2121739 is about 128.4982815558.

The spelling of 2121739 in words is "two million, one hundred twenty-one thousand, seven hundred thirty-nine".