1644102155412 has 36 divisors (see below), whose sum is σ = 4155965893716. Its totient is φ = 548028645120.

The previous prime is 1644102155383. The next prime is 1644102155473. The reversal of 1644102155412 is 2145512014461.

1644102155412 is a `hidden beast` number, since 1 + 6 + 4 + 4 + 102 + 1 + 5 + 541 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1511630906256 + 132471249156 = 1229484^2 + 363966^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×1644102155412³ (a number of 38 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5395612 + ... + 5692172.

Almost surely, 2^{1644102155412} is an apocalyptic number.

1644102155412 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1644102155412 is an abundant number, since it is smaller than the sum of its proper divisors (2511863738304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1644102155412 is a wasteful number, since it uses less digits than its factorization.

1644102155412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450568 (or 450563 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

Adding to 1644102155412 its reverse (2145512014461), we get a palindrome (3789614169873).

The spelling of 1644102155412 in words is "one trillion, six hundred forty-four billion, one hundred two million, one hundred fifty-five thousand, four hundred twelve".