1645180201 has 4 divisors (see below), whose sum is σ = 1880205952. Its totient is φ = 1410154452.

The previous prime is 1645180177. The next prime is 1645180211. The reversal of 1645180201 is 1020815461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1020815461 = 31 ⋅32929531.

It is a de Polignac number, because none of the positive numbers 2^k-1645180201 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1645180201.

It is not an unprimeable number, because it can be changed into a prime (1645180211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117512865 + ... + 117512878.

It is an arithmetic number, because the mean of its divisors is an integer number (470051488).

Almost surely, 2^1645180201 is an apocalyptic number.

It is an amenable number.

1645180201 is a deficient number, since it is larger than the sum of its proper divisors (235025751).

1645180201 is an equidigital number, since it uses as much as digits as its factorization.

1645180201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235025750.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 1645180201 is about 40560.8210099352. The cubic root of 1645180201 is about 1180.5140442041.

Adding to 1645180201 its reverse (1020815461), we get a palindrome (2665995662).

The spelling of 1645180201 in words is "one billion, six hundred forty-five million, one hundred eighty thousand, two hundred one".