21515410553941 has 2 divisors, whose sum is σ = 21515410553942. Its totient is φ = 21515410553940.

The previous prime is 21515410553921. The next prime is 21515410553981. The reversal of 21515410553941 is 14935501451512.

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., 17576813085841 + 3938597468100 = 4192471^2 + 1984590^2 .

It is a cyclic number.

It is not a de Polignac number, because 21515410553941 - 2⁴¹ = 19316387298389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21515410553891 and 21515410553900.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21515410553921) 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, 10757705276970 + 10757705276971.

It is an arithmetic number, because the mean of its divisors is an integer number (10757705276971).

Almost surely, 2^{21515410553941} is an apocalyptic number.

It is an amenable number.

21515410553941 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515410553941 is an equidigital number, since it uses as much as digits as its factorization.

21515410553941 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540000, while the sum is 46.

The spelling of 21515410553941 in words is "twenty-one trillion, five hundred fifteen billion, four hundred ten million, five hundred fifty-three thousand, nine hundred forty-one".