21910201 has 2 divisors, whose sum is σ = 21910202. Its totient is φ = 21910200.

The previous prime is 21910193. The next prime is 21910219. The reversal of 21910201 is 10201912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19184400 + 2725801 = 4380^2 + 1651^2 .

It is a cyclic number.

It is not a de Polignac number, because 21910201 - 2³ = 21910193 is a prime.

It is not a weakly prime, because it can be changed into another prime (21910241) 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 as a sum of consecutive naturals, namely, 10955100 + 10955101.

It is an arithmetic number, because the mean of its divisors is an integer number (10955101).

Almost surely, 2^21910201 is an apocalyptic number.

It is an amenable number.

21910201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21910201 is an equidigital number, since it uses as much as digits as its factorization.

21910201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 21910201 is about 4680.8333659723. The cubic root of 21910201 is about 279.8221702464.

The spelling of 21910201 in words is "twenty-one million, nine hundred ten thousand, two hundred one".