1645011321 has 8 divisors (see below), whose sum is σ = 2196826944. Its totient is φ = 1094934960.

The previous prime is 1645011299. The next prime is 1645011331. The reversal of 1645011321 is 1231105461.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1645011321 - 2⁶ = 1645011257 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1645011291 and 1645011300.

It is not an unprimeable number, because it can be changed into a prime (1645011331) 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, 432606 + ... + 436391.

It is an arithmetic number, because the mean of its divisors is an integer number (274603368).

Almost surely, 2^1645011321 is an apocalyptic number.

It is an amenable number.

1645011321 is a deficient number, since it is larger than the sum of its proper divisors (551815623).

1645011321 is an equidigital number, since it uses as much as digits as its factorization.

1645011321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869631.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 1645011321 is about 40558.7391446036. The cubic root of 1645011321 is about 1180.4736490276.

Adding to 1645011321 its reverse (1231105461), we get a palindrome (2876116782).

The spelling of 1645011321 in words is "one billion, six hundred forty-five million, eleven thousand, three hundred twenty-one".