1645865472 has 80 divisors (see below), whose sum is σ = 4642684992. Its totient is φ = 516341760.

The previous prime is 1645865467. The next prime is 1645865477. The reversal of 1645865472 is 2745685461.

It is an interprime number because it is at equal distance from previous prime (1645865467) and next prime (1645865477).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (1645865477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5404 + ... + 57627.

Almost surely, 2^1645865472 is an apocalyptic number.

1645865472 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645865472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2321342496).

1645865472 is an abundant number, since it is smaller than the sum of its proper divisors (2996819520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645865472 is an equidigital number, since it uses as much as digits as its factorization.

1645865472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63069 (or 63053 counting only the distinct ones).

The product of its digits is 1612800, while the sum is 48.

The square root of 1645865472 is about 40569.2675802756. The cubic root of 1645865472 is about 1180.6779289352.

The spelling of 1645865472 in words is "one billion, six hundred forty-five million, eight hundred sixty-five thousand, four hundred seventy-two".