21452985 has 32 divisors (see below), whose sum is σ = 38330880. Its totient is φ = 11384064.

The previous prime is 21452947. The next prime is 21452989. The reversal of 21452985 is 58925412.

It is not a de Polignac number, because 21452985 - 2⁷ = 21452857 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21452989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49329 + ... + 49761.

It is an arithmetic number, because the mean of its divisors is an integer number (1197840).

Almost surely, 2^21452985 is an apocalyptic number.

It is an amenable number.

21452985 is a deficient number, since it is larger than the sum of its proper divisors (16877895).

21452985 is a wasteful number, since it uses less digits than its factorization.

21452985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814 (or 808 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 21452985 is about 4631.7367153153. The cubic root of 21452985 is about 277.8620548132.

The spelling of 21452985 in words is "twenty-one million, four hundred fifty-two thousand, nine hundred eighty-five".