21227001 has 16 divisors (see below), whose sum is σ = 28874496. Its totient is φ = 13868496.

The previous prime is 21226969. The next prime is 21227023. The reversal of 21227001 is 10072212.

It is not a de Polignac number, because 21227001 - 2⁵ = 21226969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21227081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40326 + ... + 40848.

It is an arithmetic number, because the mean of its divisors is an integer number (1804656).

Almost surely, 2^21227001 is an apocalyptic number.

It is an amenable number.

21227001 is a deficient number, since it is larger than the sum of its proper divisors (7647495).

21227001 is a wasteful number, since it uses less digits than its factorization.

21227001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21227001 is about 4607.2769615034. The cubic root of 21227001 is about 276.8829500203.

Adding to 21227001 its reverse (10072212), we get a palindrome (31299213).

The spelling of 21227001 in words is "twenty-one million, two hundred twenty-seven thousand, one".