1645533369181 has 8 divisors (see below), whose sum is σ = 1772142987384. Its totient is φ = 1518928055040.

The previous prime is 1645533369173. The next prime is 1645533369187. The reversal of 1645533369181 is 1819633355461.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 98805863556 + 1546727505625 = 314334^2 + 1243675^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1645533369181 - 2³ = 1645533369173 is a prime.

It is a super-2 number, since 2×1645533369181² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645533369187) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 258976 + ... + 1832521.

It is an arithmetic number, because the mean of its divisors is an integer number (221517873423).

Almost surely, 2^{1645533369181} is an apocalyptic number.

It is an amenable number.

1645533369181 is a deficient number, since it is larger than the sum of its proper divisors (126609618203).

1645533369181 is a wasteful number, since it uses less digits than its factorization.

1645533369181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2152031.

The product of its digits is 6998400, while the sum is 55.

The spelling of 1645533369181 in words is "one trillion, six hundred forty-five billion, five hundred thirty-three million, three hundred sixty-nine thousand, one hundred eighty-one".