21928001 has 2 divisors, whose sum is σ = 21928002. Its totient is φ = 21928000.

The previous prime is 21927953. The next prime is 21928043. The reversal of 21928001 is 10082912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19571776 + 2356225 = 4424^2 + 1535^2 .

It is a cyclic number.

It is not a de Polignac number, because 21928001 - 2⁶ = 21927937 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21928301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10964000 + 10964001.

It is an arithmetic number, because the mean of its divisors is an integer number (10964001).

Almost surely, 2^21928001 is an apocalyptic number.

It is an amenable number.

21928001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21928001 is an equidigital number, since it uses as much as digits as its factorization.

21928001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 21928001 is about 4682.7343507827. The cubic root of 21928001 is about 279.8979262290.

The spelling of 21928001 in words is "twenty-one million, nine hundred twenty-eight thousand, one".