1644252475 has 12 divisors (see below), whose sum is σ = 2039383360. Its totient is φ = 1315072800.

The previous prime is 1644252473. The next prime is 1644252487. The reversal of 1644252475 is 5742524461.

It is a happy number.

It is not a de Polignac number, because 1644252475 - 2¹ = 1644252473 is a prime.

It is a super-3 number, since 3×1644252475³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644252473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165910 + ... + 175540.

Almost surely, 2^1644252475 is an apocalyptic number.

1644252475 is a deficient number, since it is larger than the sum of its proper divisors (395130885).

1644252475 is an equidigital number, since it uses as much as digits as its factorization.

1644252475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16470 (or 16465 counting only the distinct ones).

The product of its digits is 268800, while the sum is 40.

The square root of 1644252475 is about 40549.3831642357. The cubic root of 1644252475 is about 1180.2921030660.

The spelling of 1644252475 in words is "one billion, six hundred forty-four million, two hundred fifty-two thousand, four hundred seventy-five".