21113343437 has 2 divisors, whose sum is σ = 21113343438. Its totient is φ = 21113343436.

The previous prime is 21113343289. The next prime is 21113343467. The reversal of 21113343437 is 73434331112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20156616676 + 956726761 = 141974^2 + 30931^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113343437 - 2³⁰ = 20039601613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113343467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556671718 + 10556671719.

It is an arithmetic number, because the mean of its divisors is an integer number (10556671719).

Almost surely, 2^21113343437 is an apocalyptic number.

It is an amenable number.

21113343437 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113343437 is an equidigital number, since it uses as much as digits as its factorization.

21113343437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 32.

Adding to 21113343437 its reverse (73434331112), we get a palindrome (94547674549).

The spelling of 21113343437 in words is "twenty-one billion, one hundred thirteen million, three hundred forty-three thousand, four hundred thirty-seven".