1684245906225 has 81 divisors (see below), whose sum is σ = 3037702305729. Its totient is φ = 892045497600.

The previous prime is 1684245906223. The next prime is 1684245906227. The reversal of 1684245906225 is 5226095424861.

The square root of 1684245906225 is 1297785.

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

1684245906225 is a `hidden beast` number, since 1 + 6 + 8 + 4 + 2 + 4 + 5 + 9 + 0 + 622 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (1684245906223) and next prime (1684245906227).

It can be written as a sum of positive squares in 4 ways, for example, as 25064905761 + 1659181000464 = 158319^2 + 1288092^2 .

It is not a de Polignac number, because 1684245906225 - 2¹ = 1684245906223 is a prime.

It is a super-3 number, since 3×1684245906225³ (a number of 38 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1684245906223) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 4691492596 + ... + 4691492954.

Almost surely, 2^{1684245906225} is an apocalyptic number.

1684245906225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1684245906225 is the 1297785-th square number.

1684245906225 is the 648893-rd centered octagonal number.

It is an amenable number.

1684245906225 is a deficient number, since it is larger than the sum of its proper divisors (1353456399504).

1684245906225 is an frugal number, since it uses more digits than its factorization.

1684245906225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 54.

The spelling of 1684245906225 in words is "one trillion, six hundred eighty-four billion, two hundred forty-five million, nine hundred six thousand, two hundred twenty-five".