2121000421 has 2 divisors, whose sum is σ = 2121000422. Its totient is φ = 2121000420.

The previous prime is 2121000391. The next prime is 2121000467. The reversal of 2121000421 is 1240001212.

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., 1761480900 + 359519521 = 41970^2 + 18961^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121000421 - 2²⁵ = 2087445989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121000491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060500210 + 1060500211.

It is an arithmetic number, because the mean of its divisors is an integer number (1060500211).

Almost surely, 2^2121000421 is an apocalyptic number.

It is an amenable number.

2121000421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121000421 is an equidigital number, since it uses as much as digits as its factorization.

2121000421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2121000421 is about 46054.3203293676. The cubic root of 2121000421 is about 1284.8336970811.

Adding to 2121000421 its reverse (1240001212), we get a palindrome (3361001633).

The spelling of 2121000421 in words is "two billion, one hundred twenty-one million, four hundred twenty-one", and thus it is an aban number.