21982510225 has 27 divisors (see below), whose sum is σ = 29529343539. Its totient is φ = 16226121600.

The previous prime is 21982510211. The next prime is 21982510241. The reversal of 21982510225 is 52201528912.

The square root of 21982510225 is 148265.

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

It can be written as a sum of positive squares in 13 ways, for example, as 19325726289 + 2656783936 = 139017^2 + 51544^2 .

It is not a de Polignac number, because 21982510225 - 2¹³ = 21982502033 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9636085 + ... + 9638365.

Almost surely, 2^21982510225 is an apocalyptic number.

21982510225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21982510225 is the 148265-th square number.

21982510225 is the 74133-rd centered octagonal number.

It is an amenable number.

21982510225 is a deficient number, since it is larger than the sum of its proper divisors (7546833314).

21982510225 is an frugal number, since it uses more digits than its factorization.

21982510225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4598 (or 2299 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 21982510225 in words is "twenty-one billion, nine hundred eighty-two million, five hundred ten thousand, two hundred twenty-five".