1617919920 has 400 divisors, whose sum is σ = 6271071840. Its totient is φ = 384196608.

The previous prime is 1617919879. The next prime is 1617919943. The reversal of 1617919920 is 299197161.

1617919920 is a `hidden beast` number, since 1 + 617 + 9 + 1 + 9 + 9 + 20 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2092654 + ... + 2093426.

Almost surely, 2^1617919920 is an apocalyptic number.

1617919920 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 1617919920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3135535920).

1617919920 is an abundant number, since it is smaller than the sum of its proper divisors (4653151920).

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

1617919920 is a wasteful number, since it uses less digits than its factorization.

1617919920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834 (or 819 counting only the distinct ones).

The product of its (nonzero) digits is 61236, while the sum is 45.

The square root of 1617919920 is about 40223.3752934783. The cubic root of 1617919920 is about 1173.9574080496.

The spelling of 1617919920 in words is "one billion, six hundred seventeen million, nine hundred nineteen thousand, nine hundred twenty".