21211401 has 4 divisors (see below), whose sum is σ = 28281872. Its totient is φ = 14140932.

The previous prime is 21211387. The next prime is 21211403. The reversal of 21211401 is 10411212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21211401 - 2⁵ = 21211369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3535231 + ... + 3535236.

It is an arithmetic number, because the mean of its divisors is an integer number (7070468).

Almost surely, 2^21211401 is an apocalyptic number.

It is an amenable number.

21211401 is a deficient number, since it is larger than the sum of its proper divisors (7070471).

21211401 is an equidigital number, since it uses as much as digits as its factorization.

21211401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7070470.

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

The square root of 21211401 is about 4605.5836763650. The cubic root of 21211401 is about 276.8151051000.

Adding to 21211401 its reverse (10411212), we get a palindrome (31622613).

It can be divided in two parts, 21211 and 401, that added together give a palindrome (21612).

The spelling of 21211401 in words is "twenty-one million, two hundred eleven thousand, four hundred one".