21748745238025 has 45 divisors (see below), whose sum is σ = 29221030373651. Its totient is φ = 16057701809760.

The previous prime is 21748745237977. The next prime is 21748745238079. The reversal of 21748745238025 is 52083254784712.

The square root of 21748745238025 is 4663555.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 21338884076409 + 409861161616 = 4619403^2 + 640204^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21748745238025 is a prime.

It is a super-2 number, since 2×21748745238025² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 3940701216 + ... + 3940706734.

Almost surely, 2^{21748745238025} is an apocalyptic number.

21748745238025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21748745238025 is the 4663555-th square number.

21748745238025 is the 2331778-th centered octagonal number.

It is an amenable number.

21748745238025 is a deficient number, since it is larger than the sum of its proper divisors (7472285135626).

21748745238025 is an frugal number, since it uses more digits than its factorization.

21748745238025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11100 (or 5537 counting only the distinct ones).

The product of its (nonzero) digits is 30105600, while the sum is 58.

The spelling of 21748745238025 in words is "twenty-one trillion, seven hundred forty-eight billion, seven hundred forty-five million, two hundred thirty-eight thousand, twenty-five".