1645601642061 has 16 divisors (see below), whose sum is σ = 2444395013760. Its totient is φ = 977758004160.

The previous prime is 1645601642057. The next prime is 1645601642089. The reversal of 1645601642061 is 1602461065461.

It is a happy number.

It is not a de Polignac number, because 1645601642061 - 2² = 1645601642057 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645601642011) 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, 727497385 + ... + 727499646.

It is an arithmetic number, because the mean of its divisors is an integer number (152774688360).

Almost surely, 2^{1645601642061} is an apocalyptic number.

It is an amenable number.

1645601642061 is a deficient number, since it is larger than the sum of its proper divisors (798793371699).

1645601642061 is a wasteful number, since it uses less digits than its factorization.

1645601642061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1454997076.

The product of its (nonzero) digits is 207360, while the sum is 42.

The spelling of 1645601642061 in words is "one trillion, six hundred forty-five billion, six hundred one million, six hundred forty-two thousand, sixty-one".