21013251037 has 2 divisors, whose sum is σ = 21013251038. Its totient is φ = 21013251036.

The previous prime is 21013251031. The next prime is 21013251089. The reversal of 21013251037 is 73015231012.

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., 20556103876 + 457147161 = 143374^2 + 21381^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013251037 - 2¹¹ = 21013248989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013251031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506625518 + 10506625519.

It is an arithmetic number, because the mean of its divisors is an integer number (10506625519).

Almost surely, 2^21013251037 is an apocalyptic number.

It is an amenable number.

21013251037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013251037 is an equidigital number, since it uses as much as digits as its factorization.

21013251037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

Adding to 21013251037 its reverse (73015231012), we get a palindrome (94028482049).

The spelling of 21013251037 in words is "twenty-one billion, thirteen million, two hundred fifty-one thousand, thirty-seven".