1662771565225 has 27 divisors (see below), whose sum is σ = 2135626355343. Its totient is φ = 1284203269440.

The previous prime is 1662771565201. The next prime is 1662771565229. The reversal of 1662771565225 is 5225651772661.

The square root of 1662771565225 is 1289485.

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 1553181435289 + 109590129936 = 1246267^2 + 331044^2 .

It is not a de Polignac number, because 1662771565225 - 2¹³ = 1662771557033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1662771565229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 186970879 + ... + 186979771.

Almost surely, 2^{1662771565225} is an apocalyptic number.

1662771565225 is the 1289485-th square number.

1662771565225 is the 644743-rd centered octagonal number.

It is an amenable number.

1662771565225 is a deficient number, since it is larger than the sum of its proper divisors (472854790118).

1662771565225 is an frugal number, since it uses more digits than its factorization.

1662771565225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17854 (or 8927 counting only the distinct ones).

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

The spelling of 1662771565225 in words is "one trillion, six hundred sixty-two billion, seven hundred seventy-one million, five hundred sixty-five thousand, two hundred twenty-five".