1985509764 has 216 divisors, whose sum is σ = 6168489600. Its totient is φ = 527357952.

The previous prime is 1985509759. The next prime is 1985509769. The reversal of 1985509764 is 4679055891.

1985509764 is a `hidden beast` number, since 19 + 8 + 550 + 9 + 76 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (1985509759) and next prime (1985509769).

It is a self number, because there is not a number n which added to its sum of digits gives 1985509764.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985509769) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 9977337 + ... + 9977535.

Almost surely, 2^1985509764 is an apocalyptic number.

1985509764 is a gapful number since it is divisible by the number (14) 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 1985509764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3084244800).

1985509764 is an abundant number, since it is smaller than the sum of its proper divisors (4182979836).

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

1985509764 is a wasteful number, since it uses less digits than its factorization.

1985509764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387 (or 365 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The square root of 1985509764 is about 44559.0592809139. The cubic root of 1985509764 is about 1256.8709128987.

The spelling of 1985509764 in words is "one billion, nine hundred eighty-five million, five hundred nine thousand, seven hundred sixty-four".