21162525516425 has 6 divisors (see below), whose sum is σ = 26241531640398. Its totient is φ = 16930020413120.

The previous prime is 21162525516409. The next prime is 21162525516463. The reversal of 21162525516425 is 52461552526112.

It can be written as a sum of positive squares in 3 ways, for example, as 3401265439504 + 17761260076921 = 1844252^2 + 4214411^2 .

It is not a de Polignac number, because 21162525516425 - 2⁴ = 21162525516409 is a prime.

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 21162525516425.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 423250510304 + ... + 423250510353.

It is an arithmetic number, because the mean of its divisors is an integer number (4373588606733).

Almost surely, 2^{21162525516425} is an apocalyptic number.

21162525516425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21162525516425 is a deficient number, since it is larger than the sum of its proper divisors (5079006123973).

21162525516425 is an equidigital number, since it uses as much as digits as its factorization.

21162525516425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846501020667 (or 846501020662 counting only the distinct ones).

The product of its digits is 1440000, while the sum is 47.

The spelling of 21162525516425 in words is "twenty-one trillion, one hundred sixty-two billion, five hundred twenty-five million, five hundred sixteen thousand, four hundred twenty-five".