21500514004457 has 2 divisors, whose sum is σ = 21500514004458. Its totient is φ = 21500514004456.

The previous prime is 21500514004451. The next prime is 21500514004481. The reversal of 21500514004457 is 75440041500512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20976180160576 + 524333843881 = 4579976^2 + 724109^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21500514004457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21500514004457.

It is not a weakly prime, because it can be changed into another prime (21500514004451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10750257002228 + 10750257002229.

It is an arithmetic number, because the mean of its divisors is an integer number (10750257002229).

Almost surely, 2^{21500514004457} is an apocalyptic number.

It is an amenable number.

21500514004457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21500514004457 is an equidigital number, since it uses as much as digits as its factorization.

21500514004457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112000, while the sum is 38.

Adding to 21500514004457 its reverse (75440041500512), we get a palindrome (96940555504969).

The spelling of 21500514004457 in words is "twenty-one trillion, five hundred billion, five hundred fourteen million, four thousand, four hundred fifty-seven".