1985521356 has 480 divisors, whose sum is σ = 7027148800. Its totient is φ = 480090240.

The previous prime is 1985521339. The next prime is 1985521357. The reversal of 1985521356 is 6531255891.

1985521356 is a `hidden beast` number, since 1 + 98 + 5 + 521 + 35 + 6 = 666.

Its product of digits (324000) is a multiple of the sum of its prime divisors (75).

It is not an unprimeable number, because it can be changed into a prime (1985521357) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 64049061 + ... + 64049091.

Almost surely, 2^1985521356 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1985521356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3513574400).

1985521356 is an abundant number, since it is smaller than the sum of its proper divisors (5041627444).

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

1985521356 is a wasteful number, since it uses less digits than its factorization.

1985521356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 75 counting only the distinct ones).

The product of its digits is 324000, while the sum is 45.

The square root of 1985521356 is about 44559.1893552834. The cubic root of 1985521356 is about 1256.8733588901.

The spelling of 1985521356 in words is "one billion, nine hundred eighty-five million, five hundred twenty-one thousand, three hundred fifty-six".