21515445405101 has 16 divisors (see below), whose sum is σ = 22732311813120. Its totient is φ = 20336793586560.

The previous prime is 21515445405067. The next prime is 21515445405121. The reversal of 21515445405101 is 10150454451512.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21515445405101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515445405121) 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 in 15 ways as a sum of consecutive naturals, for example, 45919766 + ... + 46385943.

It is an arithmetic number, because the mean of its divisors is an integer number (1420769488320).

Almost surely, 2^{21515445405101} is an apocalyptic number.

It is an amenable number.

21515445405101 is a deficient number, since it is larger than the sum of its proper divisors (1216866408019).

21515445405101 is a wasteful number, since it uses less digits than its factorization.

21515445405101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92305916.

The product of its (nonzero) digits is 80000, while the sum is 38.

Adding to 21515445405101 its reverse (10150454451512), we get a palindrome (31665899856613).

The spelling of 21515445405101 in words is "twenty-one trillion, five hundred fifteen billion, four hundred forty-five million, four hundred five thousand, one hundred one".