21759752620225 has 9 divisors (see below), whose sum is σ = 26982122170467. Its totient is φ = 17407783437240.

The previous prime is 21759752620223. The next prime is 21759752620313. The reversal of 21759752620225 is 52202625795712.

The square root of 21759752620225 is 4664735.

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

It can be written as a sum of positive squares in only one way, i.e., 7833510943281 + 13926241676944 = 2798841^2 + 3731788^2 .

It is not a de Polignac number, because 21759752620225 - 2¹ = 21759752620223 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21759752620223) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22857202 + ... + 23790148.

Almost surely, 2^{21759752620225} is an apocalyptic number.

21759752620225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21759752620225 is the 4664735-th square number.

21759752620225 is the 2332368-th centered octagonal number.

It is an amenable number.

21759752620225 is a deficient number, since it is larger than the sum of its proper divisors (5222369550242).

21759752620225 is an frugal number, since it uses more digits than its factorization.

21759752620225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1865904 (or 932952 counting only the distinct ones).

The product of its (nonzero) digits is 10584000, while the sum is 55.

The spelling of 21759752620225 in words is "twenty-one trillion, seven hundred fifty-nine billion, seven hundred fifty-two million, six hundred twenty thousand, two hundred twenty-five".