1643138895653 has 4 divisors (see below), whose sum is σ = 1643142763200. Its totient is φ = 1643135028108.

The previous prime is 1643138895649. The next prime is 1643138895661. The reversal of 1643138895653 is 3565988313461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1643138895653 - 2² = 1643138895649 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643138895683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1204925 + ... + 2176722.

It is an arithmetic number, because the mean of its divisors is an integer number (410785690800).

Almost surely, 2^{1643138895653} is an apocalyptic number.

It is an amenable number.

1643138895653 is a deficient number, since it is larger than the sum of its proper divisors (3867547).

1643138895653 is an equidigital number, since it uses as much as digits as its factorization.

1643138895653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3867546.

The product of its digits is 55987200, while the sum is 62.

The spelling of 1643138895653 in words is "one trillion, six hundred forty-three billion, one hundred thirty-eight million, eight hundred ninety-five thousand, six hundred fifty-three".