985025720521 has 4 divisors (see below), whose sum is σ = 985027713412. Its totient is φ = 985023727632.

The previous prime is 985025720501. The next prime is 985025720557. The reversal of 985025720521 is 125027520589.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 150516065296 + 834509655225 = 387964^2 + 913515^2 .

It is a cyclic number.

It is not a de Polignac number, because 985025720521 - 2¹⁵ = 985025687753 is a prime.

It is a super-2 number, since 2×985025720521² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (985025720501) 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 3 ways as a sum of consecutive naturals, for example, 365095 + ... + 1450291.

It is an arithmetic number, because the mean of its divisors is an integer number (246256928353).

Almost surely, 2^985025720521 is an apocalyptic number.

It is an amenable number.

985025720521 is a deficient number, since it is larger than the sum of its proper divisors (1992891).

985025720521 is a wasteful number, since it uses less digits than its factorization.

985025720521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992890.

The product of its (nonzero) digits is 504000, while the sum is 46.

The spelling of 985025720521 in words is "nine hundred eighty-five billion, twenty-five million, seven hundred twenty thousand, five hundred twenty-one".