1985605240 has 32 divisors (see below), whose sum is σ = 4562671680. Its totient is φ = 777342592.

The previous prime is 1985605213. The next prime is 1985605243. The reversal of 1985605240 is 425065891.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1985605193 and 1985605202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985605243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 526207 + ... + 529966.

It is an arithmetic number, because the mean of its divisors is an integer number (142583490).

Almost surely, 2^1985605240 is an apocalyptic number.

1985605240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1985605240 is an abundant number, since it is smaller than the sum of its proper divisors (2577066440).

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

1985605240 is a wasteful number, since it uses less digits than its factorization.

1985605240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056231 (or 1056227 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 1985605240 is about 44560.1306102215. The cubic root of 1985605240 is about 1256.8910587048.

The spelling of 1985605240 in words is "one billion, nine hundred eighty-five million, six hundred five thousand, two hundred forty".