1645728440231 has 8 divisors (see below), whose sum is σ = 1701025603200. Its totient is φ = 1590569349120.

The previous prime is 1645728440171. The next prime is 1645728440309. The reversal of 1645728440231 is 1320448275461.

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 1645728440231 - 2¹⁰ = 1645728439207 is a prime.

It is a super-2 number, since 2×1645728440231² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645728446231) 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, 34493726 + ... + 34541403.

It is an arithmetic number, because the mean of its divisors is an integer number (212628200400).

Almost surely, 2^{1645728440231} is an apocalyptic number.

1645728440231 is a deficient number, since it is larger than the sum of its proper divisors (55297162969).

1645728440231 is an equidigital number, since it uses as much as digits as its factorization.

1645728440231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69035929.

The product of its (nonzero) digits is 1290240, while the sum is 47.

The spelling of 1645728440231 in words is "one trillion, six hundred forty-five billion, seven hundred twenty-eight million, four hundred forty thousand, two hundred thirty-one".