2012400021 has 4 divisors (see below), whose sum is σ = 2683200032. Its totient is φ = 1341600012.

The previous prime is 2012400011. The next prime is 2012400083. The reversal of 2012400021 is 1200042102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2012400021 - 2⁹ = 2012399509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2012400011) 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 in 3 ways as a sum of consecutive naturals, for example, 335400001 + ... + 335400006.

It is an arithmetic number, because the mean of its divisors is an integer number (670800008).

Almost surely, 2^2012400021 is an apocalyptic number.

It is an amenable number.

2012400021 is a deficient number, since it is larger than the sum of its proper divisors (670800011).

2012400021 is an equidigital number, since it uses as much as digits as its factorization.

2012400021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670800010.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2012400021 is about 44859.7817761076. The cubic root of 2012400021 is about 1262.5195283193.

Adding to 2012400021 its reverse (1200042102), we get a palindrome (3212442123).

The spelling of 2012400021 in words is "two billion, twelve million, four hundred thousand, twenty-one".