3644641249921 has 16 divisors (see below), whose sum is σ = 4224261749760. Its totient is φ = 3079766183760.

The previous prime is 3644641249877. The next prime is 3644641250057. The reversal of 3644641249921 is 1299421464463.

It is not a de Polignac number, because 3644641249921 - 2¹⁵ = 3644641217153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3644641243921) 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, 7183350 + ... + 7673968.

It is an arithmetic number, because the mean of its divisors is an integer number (264016359360).

Almost surely, 2^{3644641249921} is an apocalyptic number.

It is an amenable number.

3644641249921 is a deficient number, since it is larger than the sum of its proper divisors (579620499839).

3644641249921 is a wasteful number, since it uses less digits than its factorization.

3644641249921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505644.

The product of its digits is 8957952, while the sum is 55.

The spelling of 3644641249921 in words is "three trillion, six hundred forty-four billion, six hundred forty-one million, two hundred forty-nine thousand, nine hundred twenty-one".