21500231670505 has 16 divisors (see below), whose sum is σ = 29618256374784. Its totient is φ = 14676903817920.

The previous prime is 21500231670503. The next prime is 21500231670557. The reversal of 21500231670505 is 50507613200512.

It is not a de Polignac number, because 21500231670505 - 2¹ = 21500231670503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21500231670503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1377329266 + ... + 1377344875.

It is an arithmetic number, because the mean of its divisors is an integer number (1851141023424).

Almost surely, 2^{21500231670505} is an apocalyptic number.

It is an amenable number.

21500231670505 is a deficient number, since it is larger than the sum of its proper divisors (8118024704279).

21500231670505 is a wasteful number, since it uses less digits than its factorization.

21500231670505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2754674376.

The product of its (nonzero) digits is 63000, while the sum is 37.

The spelling of 21500231670505 in words is "twenty-one trillion, five hundred billion, two hundred thirty-one million, six hundred seventy thousand, five hundred five".