21845601 has 6 divisors (see below), whose sum is σ = 31554770. Its totient is φ = 14563728.

The previous prime is 21845597. The next prime is 21845627. The reversal of 21845601 is 10654812.

21845601 is a `hidden beast` number, since 2 + 18 + 45 + 601 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11289600 + 10556001 = 3360^2 + 3249^2 .

It is not a de Polignac number, because 21845601 - 2² = 21845597 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21845401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1213636 + ... + 1213653.

Almost surely, 2^21845601 is an apocalyptic number.

It is an amenable number.

21845601 is a deficient number, since it is larger than the sum of its proper divisors (9709169).

21845601 is a wasteful number, since it uses less digits than its factorization.

21845601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2427295 (or 2427292 counting only the distinct ones).

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

The square root of 21845601 is about 4673.9277914833. The cubic root of 21845601 is about 279.5468904510.

The spelling of 21845601 in words is "twenty-one million, eight hundred forty-five thousand, six hundred one".