21506205214535 has 8 divisors (see below), whose sum is σ = 25825281405216. Its totient is φ = 17193074073120.

The previous prime is 21506205214531. The next prime is 21506205214573. The reversal of 21506205214535 is 53541250260512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21506205214535 - 2² = 21506205214531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21506205214492 and 21506205214501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506205214531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1486254356 + ... + 1486268825.

It is an arithmetic number, because the mean of its divisors is an integer number (3228160175652).

Almost surely, 2^{21506205214535} is an apocalyptic number.

21506205214535 is a deficient number, since it is larger than the sum of its proper divisors (4319076190681).

21506205214535 is a wasteful number, since it uses less digits than its factorization.

21506205214535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2972524633.

The product of its (nonzero) digits is 360000, while the sum is 41.

The spelling of 21506205214535 in words is "twenty-one trillion, five hundred six billion, two hundred five million, two hundred fourteen thousand, five hundred thirty-five".