21111401 has 4 divisors (see below), whose sum is σ = 22029312. Its totient is φ = 20193492.

The previous prime is 21111397. The next prime is 21111457. The reversal of 21111401 is 10411112.

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 a cyclic number.

It is not a de Polignac number, because 21111401 - 2² = 21111397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111481) 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, 458921 + ... + 458966.

It is an arithmetic number, because the mean of its divisors is an integer number (5507328).

Almost surely, 2^21111401 is an apocalyptic number.

It is an amenable number.

21111401 is a deficient number, since it is larger than the sum of its proper divisors (917911).

21111401 is an equidigital number, since it uses as much as digits as its factorization.

21111401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917910.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 21111401 is about 4594.7144633807. The cubic root of 21111401 is about 276.3794097586.

Adding to 21111401 its reverse (10411112), we get a palindrome (31522513).

It can be divided in two parts, 21111 and 401, that added together give a palindrome (21512).

The spelling of 21111401 in words is "twenty-one million, one hundred eleven thousand, four hundred one".