1639423968 has 576 divisors, whose sum is σ = 6081143040. Its totient is φ = 380878848.

The previous prime is 1639423937. The next prime is 1639423993. The reversal of 1639423968 is 8693249361.

It is a Harshad number since it is a multiple of its sum of digits (51).

Its product of digits (1679616) is a multiple of the sum of its prime divisors (144).

It is a self number, because there is not a number n which added to its sum of digits gives 1639423968.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 19752055 + ... + 19752137.

It is an arithmetic number, because the mean of its divisors is an integer number (10557540).

Almost surely, 2^1639423968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1639423968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3040571520).

1639423968 is an abundant number, since it is smaller than the sum of its proper divisors (4441719072).

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

1639423968 is a wasteful number, since it uses less digits than its factorization.

1639423968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 144 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 51.

The square root of 1639423968 is about 40489.8007898285. The cubic root of 1639423968 is about 1179.1356228436.

It can be divided in two parts, 163942 and 3968, that added together give a triangular number (167910 = T₅₇₉).

The spelling of 1639423968 in words is "one billion, six hundred thirty-nine million, four hundred twenty-three thousand, nine hundred sixty-eight".