1985605920 has 96 divisors (see below), whose sum is σ = 6949635840. Its totient is φ = 529493760.

The previous prime is 1985605891. The next prime is 1985605927. The reversal of 1985605920 is 295065891.

1985605920 is a `hidden beast` number, since 1 + 9 + 8 + 56 + 0 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is not an unprimeable number, because it can be changed into a prime (1985605927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 225496 + ... + 234135.

It is an arithmetic number, because the mean of its divisors is an integer number (72392040).

Almost surely, 2^1985605920 is an apocalyptic number.

1985605920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1985605920 is an abundant number, since it is smaller than the sum of its proper divisors (4964029920).

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

1985605920 is a wasteful number, since it uses less digits than its factorization.

1985605920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459655 (or 459641 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The square root of 1985605920 is about 44560.1382403601. The cubic root of 1985605920 is about 1256.8912021851.

It can be divided in two parts, 198560 and 5920, that added together give a triangular number (204480 = T₆₃₉).

The spelling of 1985605920 in words is "one billion, nine hundred eighty-five million, six hundred five thousand, nine hundred twenty".