1684401644025 has 135 divisors (see below), whose sum is σ = 3157424389119. Its totient is φ = 887725980000.

The previous prime is 1684401643933. The next prime is 1684401644059. The reversal of 1684401644025 is 5204461044861.

The square root of 1684401644025 is 1297845.

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

1684401644025 is a `hidden beast` number, since 1 + 6 + 8 + 440 + 164 + 40 + 2 + 5 = 666.

It can be written as a sum of positive squares in only one way, i.e., 606384591849 + 1078017052176 = 778707^2 + 1038276^2 .

It is a tau number, because it is divible by the number of its divisors (135).

It is not a de Polignac number, because 1684401644025 - 2⁹ = 1684401643513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 134 ways as a sum of consecutive naturals, for example, 8818856680 + ... + 8818856870.

Almost surely, 2^{1684401644025} is an apocalyptic number.

1684401644025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1684401644025 is the 1297845-th square number.

1684401644025 is the 648923-rd centered octagonal number.

It is an amenable number.

1684401644025 is a deficient number, since it is larger than the sum of its proper divisors (1473022745094).

1684401644025 is an frugal number, since it uses more digits than its factorization.

1684401644025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706 (or 350 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 45.

Adding to 1684401644025 its reverse (5204461044861), we get a palindrome (6888862688886).

The spelling of 1684401644025 in words is "one trillion, six hundred eighty-four billion, four hundred one million, six hundred forty-four thousand, twenty-five".