21515445525135 has 64 divisors (see below), whose sum is σ = 37239912456192. Its totient is φ = 10565953069056.

The previous prime is 21515445525121. The next prime is 21515445525143. The reversal of 21515445525135 is 53152554451512.

It is not a de Polignac number, because 21515445525135 - 2¹⁴ = 21515445508751 is a prime.

It is a super-2 number, since 2×21515445525135² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30124887 + ... + 30830823.

It is an arithmetic number, because the mean of its divisors is an integer number (581873632128).

Almost surely, 2^{21515445525135} is an apocalyptic number.

21515445525135 is a deficient number, since it is larger than the sum of its proper divisors (15724466931057).

21515445525135 is a wasteful number, since it uses less digits than its factorization.

21515445525135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708552.

The product of its digits is 3000000, while the sum is 48.

Adding to 21515445525135 its reverse (53152554451512), we get a palindrome (74667999976647).

The spelling of 21515445525135 in words is "twenty-one trillion, five hundred fifteen billion, four hundred forty-five million, five hundred twenty-five thousand, one hundred thirty-five".