21534113437 has 2 divisors, whose sum is σ = 21534113438. Its totient is φ = 21534113436.

The previous prime is 21534113417. The next prime is 21534113441. The reversal of 21534113437 is 73431143512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17154188676 + 4379924761 = 130974^2 + 66181^2 .

It is a cyclic number.

It is not a de Polignac number, because 21534113437 - 2⁷ = 21534113309 is a prime.

It is a super-3 number, since 3×21534113437³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21534113417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767056718 + 10767056719.

It is an arithmetic number, because the mean of its divisors is an integer number (10767056719).

Almost surely, 2^21534113437 is an apocalyptic number.

It is an amenable number.

21534113437 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534113437 is an equidigital number, since it uses as much as digits as its factorization.

21534113437 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

Adding to 21534113437 its reverse (73431143512), we get a palindrome (94965256949).

The spelling of 21534113437 in words is "twenty-one billion, five hundred thirty-four million, one hundred thirteen thousand, four hundred thirty-seven".