1858409665225 has 27 divisors (see below), whose sum is σ = 2354907515701. Its totient is φ = 1454844392000.

The previous prime is 1858409665219. The next prime is 1858409665241. The reversal of 1858409665225 is 5225669048581.

The square root of 1858409665225 is 1363235.

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 446238696121 + 1412170969104 = 668011^2 + 1188348^2 .

It is not a de Polignac number, because 1858409665225 - 2²³ = 1858401276617 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 (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 320357325 + ... + 320363125.

Almost surely, 2^{1858409665225} is an apocalyptic number.

1858409665225 is the 1363235-th square number.

1858409665225 is the 681618-th centered octagonal number.

It is an amenable number.

1858409665225 is a deficient number, since it is larger than the sum of its proper divisors (496497850476).

1858409665225 is an frugal number, since it uses more digits than its factorization.

1858409665225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11706 (or 5853 counting only the distinct ones).

The product of its (nonzero) digits is 41472000, while the sum is 61.

The spelling of 1858409665225 in words is "one trillion, eight hundred fifty-eight billion, four hundred nine million, six hundred sixty-five thousand, two hundred twenty-five".