21507531773105 has 64 divisors (see below), whose sum is σ = 30331812469248. Its totient is φ = 14335420968960.

The previous prime is 21507531773081. The next prime is 21507531773159. The reversal of 21507531773105 is 50137713570512.

It is not a de Polignac number, because 21507531773105 - 2¹⁸ = 21507531510961 is a prime.

It is a super-2 number, since 2×21507531773105² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21507531773105.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 505360487 + ... + 505403043.

It is an arithmetic number, because the mean of its divisors is an integer number (473934569832).

Almost surely, 2^{21507531773105} is an apocalyptic number.

It is an amenable number.

21507531773105 is a deficient number, since it is larger than the sum of its proper divisors (8824280696143).

21507531773105 is a wasteful number, since it uses less digits than its factorization.

21507531773105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45146.

The product of its (nonzero) digits is 771750, while the sum is 47.

The spelling of 21507531773105 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-one million, seven hundred seventy-three thousand, one hundred five".