1645542221327 has 8 divisors (see below), whose sum is σ = 1732755198960. Its totient is φ = 1558389792960.

The previous prime is 1645542221299. The next prime is 1645542221413. The reversal of 1645542221327 is 7231222455461.

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 1645542221327 - 2²⁸ = 1645273785871 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 (1645542221027) 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, 15081518 + ... + 15190235.

It is an arithmetic number, because the mean of its divisors is an integer number (216594399870).

Almost surely, 2^{1645542221327} is an apocalyptic number.

1645542221327 is a deficient number, since it is larger than the sum of its proper divisors (87212977633).

1645542221327 is a wasteful number, since it uses less digits than its factorization.

1645542221327 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30274633.

The product of its digits is 806400, while the sum is 44.

Adding to 1645542221327 its reverse (7231222455461), we get a palindrome (8876764676788).

The spelling of 1645542221327 in words is "one trillion, six hundred forty-five billion, five hundred forty-two million, two hundred twenty-one thousand, three hundred twenty-seven".