1617955920 has 240 divisors, whose sum is σ = 6281383680. Its totient is φ = 365561856.

The previous prime is 1617955903. The next prime is 1617955921. The reversal of 1617955920 is 295597161.

1617955920 is a `hidden beast` number, since 1 + 6 + 1 + 79 + 559 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1617955921) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 446757 + ... + 450363.

It is an arithmetic number, because the mean of its divisors is an integer number (26172432).

Almost surely, 2^1617955920 is an apocalyptic number.

1617955920 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 1617955920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3140691840).

1617955920 is an abundant number, since it is smaller than the sum of its proper divisors (4663427760).

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

1617955920 is a wasteful number, since it uses less digits than its factorization.

1617955920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3722 (or 3713 counting only the distinct ones).

The product of its (nonzero) digits is 170100, while the sum is 45.

The square root of 1617955920 is about 40223.8227919724. The cubic root of 1617955920 is about 1173.9661151458.

The spelling of 1617955920 in words is "one billion, six hundred seventeen million, nine hundred fifty-five thousand, nine hundred twenty".