1645494144 has 128 divisors (see below), whose sum is σ = 5034458880. Its totient is φ = 466452480.

The previous prime is 1645494143. The next prime is 1645494187. The reversal of 1645494144 is 4414945461.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1645494096 and 1645494105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645494143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349792 + ... + 354464.

It is an arithmetic number, because the mean of its divisors is an integer number (39331710).

Almost surely, 2^1645494144 is an apocalyptic number.

1645494144 is a gapful number since it is divisible by the number (14) 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 1645494144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2517229440).

1645494144 is an abundant number, since it is smaller than the sum of its proper divisors (3388964736).

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

1645494144 is a wasteful number, since it uses less digits than its factorization.

1645494144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4828 (or 4816 counting only the distinct ones).

The product of its digits is 276480, while the sum is 42.

The square root of 1645494144 is about 40564.6908530066. The cubic root of 1645494144 is about 1180.5891303150.

The spelling of 1645494144 in words is "one billion, six hundred forty-five million, four hundred ninety-four thousand, one hundred forty-four".