1811852651421 has 12 divisors (see below), whose sum is σ = 2628352776348. Its totient is φ = 1202717638464.

The previous prime is 1811852651419. The next prime is 1811852651449. The reversal of 1811852651421 is 1241562581181.

1811852651421 is a `hidden beast` number, since 1 + 8 + 11 + 85 + 26 + 514 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 891041602500 + 920811048921 = 943950^2 + 959589^2 .

It is not a de Polignac number, because 1811852651421 - 2¹ = 1811852651419 is a prime.

It is a super-2 number, since 2×1811852651421² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1811852651471) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 432008550 + ... + 432012743.

It is an arithmetic number, because the mean of its divisors is an integer number (219029398029).

Almost surely, 2^{1811852651421} is an apocalyptic number.

It is an amenable number.

1811852651421 is a deficient number, since it is larger than the sum of its proper divisors (816500124927).

1811852651421 is a wasteful number, since it uses less digits than its factorization.

1811852651421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864021532 (or 864021529 counting only the distinct ones).

The product of its digits is 153600, while the sum is 45.

The spelling of 1811852651421 in words is "one trillion, eight hundred eleven billion, eight hundred fifty-two million, six hundred fifty-one thousand, four hundred twenty-one".