21500707163425 has 24 divisors (see below), whose sum is σ = 30473013618176. Its totient is φ = 14741677520640.

The previous prime is 21500707163393. The next prime is 21500707163479. The reversal of 21500707163425 is 52436170700512.

It is a happy number.

It is not a de Polignac number, because 21500707163425 - 2⁵ = 21500707163393 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5380104 + ... + 8482153.

Almost surely, 2^{21500707163425} is an apocalyptic number.

21500707163425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21500707163425 is a deficient number, since it is larger than the sum of its proper divisors (8972306454751).

21500707163425 is a wasteful number, since it uses less digits than its factorization.

21500707163425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13871137 (or 13871132 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 43.

Adding to 21500707163425 its reverse (52436170700512), we get a palindrome (73936877863937).

The spelling of 21500707163425 in words is "twenty-one trillion, five hundred billion, seven hundred seven million, one hundred sixty-three thousand, four hundred twenty-five".