1656734689920 has 256 divisors, whose sum is σ = 5834590030080. Its totient is φ = 397729136640.

The previous prime is 1656734689873. The next prime is 1656734689921. The reversal of 1656734689920 is 299864376561.

It is not an unprimeable number, because it can be changed into a prime (1656734689921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 352711 + ... + 1854150.

It is an arithmetic number, because the mean of its divisors is an integer number (22791367305).

It is a 1-persistent number, because it is pandigital, but 2⋅1656734689920 = 3313469379840 is not.

Almost surely, 2^{1656734689920} is an apocalyptic number.

1656734689920 is a gapful number since it is divisible by the number (10) 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 1656734689920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2917295015040).

1656734689920 is an abundant number, since it is smaller than the sum of its proper divisors (4177855340160).

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

1656734689920 is a wasteful number, since it uses less digits than its factorization.

1656734689920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2206923 (or 2206911 counting only the distinct ones).

The product of its (nonzero) digits is 117573120, while the sum is 66.

The spelling of 1656734689920 in words is "one trillion, six hundred fifty-six billion, seven hundred thirty-four million, six hundred eighty-nine thousand, nine hundred twenty".