21357055504537 has 2 divisors, whose sum is σ = 21357055504538. Its totient is φ = 21357055504536.

The previous prime is 21357055504507. The next prime is 21357055504567. The reversal of 21357055504537 is 73540555075312.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21357055504507) and next prime (21357055504567).

It can be written as a sum of positive squares in only one way, i.e., 13137572927241 + 8219482577296 = 3624579^2 + 2866964^2 .

It is a cyclic number.

It is not a de Polignac number, because 21357055504537 - 2⁴³ = 12560962482329 is a prime.

It is a super-2 number, since 2×21357055504537² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21357055504507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678527752268 + 10678527752269.

It is an arithmetic number, because the mean of its divisors is an integer number (10678527752269).

Almost surely, 2^{21357055504537} is an apocalyptic number.

It is an amenable number.

21357055504537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357055504537 is an equidigital number, since it uses as much as digits as its factorization.

21357055504537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11025000, while the sum is 52.

The spelling of 21357055504537 in words is "twenty-one trillion, three hundred fifty-seven billion, fifty-five million, five hundred four thousand, five hundred thirty-seven".