21485601 has 8 divisors (see below), whose sum is σ = 31830560. Its totient is φ = 14323716.

The previous prime is 21485591. The next prime is 21485609. The reversal of 21485601 is 10658412.

It is not a de Polignac number, because 21485601 - 2⁶ = 21485537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 795763 = 21485601 / (2 + 1 + 4 + 8 + 5 + 6 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21485609) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 397855 + ... + 397908.

It is an arithmetic number, because the mean of its divisors is an integer number (3978820).

Almost surely, 2^21485601 is an apocalyptic number.

It is an amenable number.

21485601 is a deficient number, since it is larger than the sum of its proper divisors (10344959).

21485601 is an equidigital number, since it uses as much as digits as its factorization.

21485601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795772 (or 795766 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21485601 is about 4635.2563035931. The cubic root of 21485601 is about 278.0027991713.

The spelling of 21485601 in words is "twenty-one million, four hundred eighty-five thousand, six hundred one".