21485775 has 12 divisors (see below), whose sum is σ = 35523272. Its totient is φ = 11459040.

The previous prime is 21485771. The next prime is 21485797. The reversal of 21485775 is 57758412.

It is not a de Polignac number, because 21485775 - 2² = 21485771 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21485771) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143164 + ... + 143313.

Almost surely, 2^21485775 is an apocalyptic number.

21485775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21485775 is a deficient number, since it is larger than the sum of its proper divisors (14037497).

21485775 is a wasteful number, since it uses less digits than its factorization.

21485775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286490 (or 286485 counting only the distinct ones).

The product of its digits is 78400, while the sum is 39.

The square root of 21485775 is about 4635.2750727438. The cubic root of 21485775 is about 278.0035496329.

The spelling of 21485775 in words is "twenty-one million, four hundred eighty-five thousand, seven hundred seventy-five".