1639668156 has 192 divisors, whose sum is σ = 4913233920. Its totient is φ = 414305280.

The previous prime is 1639668133. The next prime is 1639668169. The reversal of 1639668156 is 6518669361.

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

It is a junction number, because it is equal to n+sod(n) for n = 1639668099 and 1639668108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6050301 + ... + 6050571.

It is an arithmetic number, because the mean of its divisors is an integer number (25589760).

Almost surely, 2^1639668156 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 1639668156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2456616960).

1639668156 is an abundant number, since it is smaller than the sum of its proper divisors (3273565764).

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

1639668156 is a wasteful number, since it uses less digits than its factorization.

1639668156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544 (or 542 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 51.

The square root of 1639668156 is about 40492.8161036004. The cubic root of 1639668156 is about 1179.1941630140.

The spelling of 1639668156 in words is "one billion, six hundred thirty-nine million, six hundred sixty-eight thousand, one hundred fifty-six".