21284177125 has 8 divisors (see below), whose sum is σ = 26562653208. Its totient is φ = 17027341600.

The previous prime is 21284177119. The next prime is 21284177137. The reversal of 21284177125 is 52177148212.

It can be written as a sum of positive squares in 4 ways, for example, as 6356713441 + 14927463684 = 79729^2 + 122178^2 .

It is not a de Polignac number, because 21284177125 - 2⁷ = 21284176997 is a prime.

It is a Duffinian number.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 85136584 + ... + 85136833.

It is an arithmetic number, because the mean of its divisors is an integer number (3320331651).

Almost surely, 2^21284177125 is an apocalyptic number.

21284177125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21284177125 is a deficient number, since it is larger than the sum of its proper divisors (5278476083).

21284177125 is an equidigital number, since it uses as much as digits as its factorization.

21284177125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170273432 (or 170273422 counting only the distinct ones).

The product of its digits is 62720, while the sum is 40.

The spelling of 21284177125 in words is "twenty-one billion, two hundred eighty-four million, one hundred seventy-seven thousand, one hundred twenty-five".