2138421409 has 2 divisors, whose sum is σ = 2138421410. Its totient is φ = 2138421408.

The previous prime is 2138421371. The next prime is 2138421421. The reversal of 2138421409 is 9041248312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2113700625 + 24720784 = 45975^2 + 4972^2 .

It is a cyclic number.

It is not a de Polignac number, because 2138421409 - 2¹⁵ = 2138388641 is a prime.

It is a super-2 number, since 2×2138421409² = 9145692244939090562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2138421479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069210704 + 1069210705.

It is an arithmetic number, because the mean of its divisors is an integer number (1069210705).

Almost surely, 2^2138421409 is an apocalyptic number.

It is an amenable number.

2138421409 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138421409 is an equidigital number, since it uses as much as digits as its factorization.

2138421409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 2138421409 is about 46243.0687671136. The cubic root of 2138421409 is about 1288.3418008760.

The spelling of 2138421409 in words is "two billion, one hundred thirty-eight million, four hundred twenty-one thousand, four hundred nine".