21585486400 has 63 divisors (see below), whose sum is σ = 53128252011. Its totient is φ = 8631843840.

The previous prime is 21585486379. The next prime is 21585486421. The reversal of 21585486400 is 468458512.

The square root of 21585486400 is 146920.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (21585486379) and next prime (21585486421).

It can be written as a sum of positive squares in 4 ways, for example, as 8321818176 + 13263668224 = 91224^2 + 115168^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5874964 + ... + 5878636.

Almost surely, 2^21585486400 is an apocalyptic number.

21585486400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21585486400 is the 146920-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21585486400

21585486400 is an abundant number, since it is smaller than the sum of its proper divisors (31542765611).

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

21585486400 is an frugal number, since it uses more digits than its factorization.

21585486400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7368 (or 3680 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 43.

The spelling of 21585486400 in words is "twenty-one billion, five hundred eighty-five million, four hundred eighty-six thousand, four hundred".