21201219937 has 2 divisors, whose sum is σ = 21201219938. Its totient is φ = 21201219936.

The previous prime is 21201219931. The next prime is 21201219953. The reversal of 21201219937 is 73991210212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20989924641 + 211295296 = 144879^2 + 14536^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201219937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201219896 and 21201219905.

It is not a weakly prime, because it can be changed into another prime (21201219931) 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, 10600609968 + 10600609969.

It is an arithmetic number, because the mean of its divisors is an integer number (10600609969).

Almost surely, 2^21201219937 is an apocalyptic number.

It is an amenable number.

21201219937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201219937 is an equidigital number, since it uses as much as digits as its factorization.

21201219937 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 37.

The spelling of 21201219937 in words is "twenty-one billion, two hundred one million, two hundred nineteen thousand, nine hundred thirty-seven".