21131632505 has 16 divisors (see below), whose sum is σ = 25781119248. Its totient is φ = 16623360000.

The previous prime is 21131632499. The next prime is 21131632573. The reversal of 21131632505 is 50523613112.

It can be written as a sum of positive squares in 8 ways, for example, as 524455801 + 20607176704 = 22901^2 + 143552^2 .

It is not a de Polignac number, because 21131632505 - 2¹⁶ = 21131566969 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1346705 + ... + 1362305.

It is an arithmetic number, because the mean of its divisors is an integer number (1611319953).

Almost surely, 2^21131632505 is an apocalyptic number.

It is an amenable number.

21131632505 is a deficient number, since it is larger than the sum of its proper divisors (4649486743).

21131632505 is a wasteful number, since it uses less digits than its factorization.

21131632505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20108.

The product of its (nonzero) digits is 5400, while the sum is 29.

The spelling of 21131632505 in words is "twenty-one billion, one hundred thirty-one million, six hundred thirty-two thousand, five hundred five".