1645944384 has 112 divisors (see below), whose sum is σ = 5016731648. Its totient is φ = 466518528.

The previous prime is 1645944383. The next prime is 1645944397. The reversal of 1645944384 is 4834495461.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×1645944384² = 5418265830442278912, which contains 22 as substring.

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 (1645944383) 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, 165867 + ... + 175509.

Almost surely, 2^1645944384 is an apocalyptic number.

1645944384 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 1645944384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2508365824).

1645944384 is an abundant number, since it is smaller than the sum of its proper divisors (3370787264).

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

1645944384 is a wasteful number, since it uses less digits than its factorization.

1645944384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9792 (or 9782 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 48.

The square root of 1645944384 is about 40570.2401274629. The cubic root of 1645944384 is about 1180.6967980691.

The spelling of 1645944384 in words is "one billion, six hundred forty-five million, nine hundred forty-four thousand, three hundred eighty-four".