21788201 has 2 divisors, whose sum is σ = 21788202. Its totient is φ = 21788200.

The previous prime is 21788183. The next prime is 21788233. The reversal of 21788201 is 10288712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 811801 = 4580^2 + 901^2 .

It is a cyclic number.

It is not a de Polignac number, because 21788201 - 2¹⁰ = 21787177 is a prime.

It is not a weakly prime, because it can be changed into another prime (21718201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10894100 + 10894101.

It is an arithmetic number, because the mean of its divisors is an integer number (10894101).

Almost surely, 2^21788201 is an apocalyptic number.

It is an amenable number.

21788201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21788201 is an equidigital number, since it uses as much as digits as its factorization.

21788201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 21788201 is about 4667.7833068813. The cubic root of 21788201 is about 279.3018362966.

The spelling of 21788201 in words is "twenty-one million, seven hundred eighty-eight thousand, two hundred one".