21436601 has 2 divisors, whose sum is σ = 21436602. Its totient is φ = 21436600.

The previous prime is 21436573. The next prime is 21436637. The reversal of 21436601 is 10663412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21381376 + 55225 = 4624^2 + 235^2 .

It is a cyclic number.

It is not a de Polignac number, because 21436601 - 2²² = 17242297 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 11.

It is not a weakly prime, because it can be changed into another prime (21436651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718300 + 10718301.

It is an arithmetic number, because the mean of its divisors is an integer number (10718301).

Almost surely, 2^21436601 is an apocalyptic number.

It is an amenable number.

21436601 is a deficient number, since it is larger than the sum of its proper divisors (1).

21436601 is an equidigital number, since it uses as much as digits as its factorization.

21436601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21436601 is about 4629.9677104706. The cubic root of 21436601 is about 277.7913008468.

The spelling of 21436601 in words is "twenty-one million, four hundred thirty-six thousand, six hundred one".