21290980066225 has 27 divisors (see below), whose sum is σ = 26455943536609. Its totient is φ = 16997291511200.

The previous prime is 21290980066099. The next prime is 21290980066231. The reversal of 21290980066225 is 52266008909212.

The square root of 21290980066225 is 4614215.

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

It can be written as a sum of positive squares in 4 ways, for example, as 12707392656049 + 8583587410176 = 3564743^2 + 2929776^2 .

It is not a de Polignac number, because 21290980066225 - 2¹⁵ = 21290980033457 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 (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 21017748819 + ... + 21017749831.

Almost surely, 2^{21290980066225} is an apocalyptic number.

21290980066225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21290980066225 is the 4614215-th square number.

21290980066225 is the 2307108-th centered octagonal number.

It is an amenable number.

21290980066225 is a deficient number, since it is larger than the sum of its proper divisors (5164963470384).

21290980066225 is an frugal number, since it uses more digits than its factorization.

21290980066225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3858 (or 1929 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 52.

The spelling of 21290980066225 in words is "twenty-one trillion, two hundred ninety billion, nine hundred eighty million, sixty-six thousand, two hundred twenty-five".