2151242421421 has 2 divisors, whose sum is σ = 2151242421422. Its totient is φ = 2151242421420.

The previous prime is 2151242421409. The next prime is 2151242421547. The reversal of 2151242421421 is 1241242421512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1670778567396 + 480463854025 = 1292586^2 + 693155^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151242421421 - 2¹⁷ = 2151242290349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2151242421221) 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, 1075621210710 + 1075621210711.

It is an arithmetic number, because the mean of its divisors is an integer number (1075621210711).

Almost surely, 2^{2151242421421} is an apocalyptic number.

It is an amenable number.

2151242421421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151242421421 is an equidigital number, since it uses as much as digits as its factorization.

2151242421421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10240, while the sum is 31.

Adding to 2151242421421 its reverse (1241242421512), we get a palindrome (3392484842933).

Subtracting from 2151242421421 its reverse (1241242421512), we obtain a palindrome (909999999909).

The spelling of 2151242421421 in words is "two trillion, one hundred fifty-one billion, two hundred forty-two million, four hundred twenty-one thousand, four hundred twenty-one".