1645571361601 has 16 divisors (see below), whose sum is σ = 1674135934848. Its totient is φ = 1617158995200.

The previous prime is 1645571361587. The next prime is 1645571361611. The reversal of 1645571361601 is 1061631755461.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1645571361601 - 2³⁷ = 1508132408129 is a prime.

It is a super-2 number, since 2×1645571361601² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1645571361611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133530426 + ... + 133542748.

It is an arithmetic number, because the mean of its divisors is an integer number (104633495928).

Almost surely, 2^{1645571361601} is an apocalyptic number.

It is an amenable number.

1645571361601 is a deficient number, since it is larger than the sum of its proper divisors (28564573247).

1645571361601 is a wasteful number, since it uses less digits than its factorization.

1645571361601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18312.

The product of its (nonzero) digits is 453600, while the sum is 46.

The spelling of 1645571361601 in words is "one trillion, six hundred forty-five billion, five hundred seventy-one million, three hundred sixty-one thousand, six hundred one".