1985773521 has 32 divisors (see below), whose sum is σ = 2802101760. Its totient is φ = 1249081344.

The previous prime is 1985773513. The next prime is 1985773529. The reversal of 1985773521 is 1253775891.

It is an interprime number because it is at equal distance from previous prime (1985773513) and next prime (1985773529).

It is not a de Polignac number, because 1985773521 - 2³ = 1985773513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1985773529) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 716280 + ... + 719046.

It is an arithmetic number, because the mean of its divisors is an integer number (87565680).

Almost surely, 2^1985773521 is an apocalyptic number.

It is an amenable number.

1985773521 is a deficient number, since it is larger than the sum of its proper divisors (816328239).

1985773521 is a wasteful number, since it uses less digits than its factorization.

1985773521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2985.

The product of its digits is 529200, while the sum is 48.

The square root of 1985773521 is about 44562.0188164764. The cubic root of 1985773521 is about 1256.9265650758.

The spelling of 1985773521 in words is "one billion, nine hundred eighty-five million, seven hundred seventy-three thousand, five hundred twenty-one".