1617920 has 52 divisors (see below), whose sum is σ = 3931680. Its totient is φ = 638976.

The previous prime is 1617893. The next prime is 1617923. The reversal of 1617920 is 297161.

It is a self number, because there is not a number n which added to its sum of digits gives 1617920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1617923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20441 + ... + 20519.

2^1617920 is an apocalyptic number.

1617920 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 1617920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1965840).

1617920 is an abundant number, since it is smaller than the sum of its proper divisors (2313760).

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

1617920 is an frugal number, since it uses more digits than its factorization.

1617920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 1617920 is about 1271.9748425185. The cubic root of 1617920 is about 117.3957427399.

The spelling of 1617920 in words is "one million, six hundred seventeen thousand, nine hundred twenty".