21213420037 has 2 divisors, whose sum is σ = 21213420038. Its totient is φ = 21213420036.

The previous prime is 21213420031. The next prime is 21213420091. The reversal of 21213420037 is 73002431212.

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., 16447036516 + 4766383521 = 128246^2 + 69039^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213420037 - 2¹⁵ = 21213387269 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21213419993 and 21213420020.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21213420031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606710018 + 10606710019.

It is an arithmetic number, because the mean of its divisors is an integer number (10606710019).

Almost surely, 2^21213420037 is an apocalyptic number.

It is an amenable number.

21213420037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213420037 is an equidigital number, since it uses as much as digits as its factorization.

21213420037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 25.

Adding to 21213420037 its reverse (73002431212), we get a palindrome (94215851249).

The spelling of 21213420037 in words is "twenty-one billion, two hundred thirteen million, four hundred twenty thousand, thirty-seven".