21401211 has 8 divisors (see below), whose sum is σ = 30730000. Its totient is φ = 13169952.

The previous prime is 21401203. The next prime is 21401251. The reversal of 21401211 is 11210412.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21401211 - 2³ = 21401203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21401251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274336 + ... + 274413.

It is an arithmetic number, because the mean of its divisors is an integer number (3841250).

Almost surely, 2^21401211 is an apocalyptic number.

21401211 is a deficient number, since it is larger than the sum of its proper divisors (9328789).

21401211 is a wasteful number, since it uses less digits than its factorization.

21401211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548765.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 21401211 is about 4626.1442908755. The cubic root of 21401211 is about 277.6383467292.

Adding to 21401211 its reverse (11210412), we get a palindrome (32611623).

It can be divided in two parts, 21401 and 211, that added together give a palindrome (21612).

The spelling of 21401211 in words is "twenty-one million, four hundred one thousand, two hundred eleven".