21422141 has 4 divisors (see below), whose sum is σ = 23070012. Its totient is φ = 19774272.

The previous prime is 21422129. The next prime is 21422143. The reversal of 21422141 is 14122412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8791225 + 12630916 = 2965^2 + 3554^2 .

It is a cyclic number.

It is not a de Polignac number, because 21422141 - 2⁶ = 21422077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422143) 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, 823916 + ... + 823941.

It is an arithmetic number, because the mean of its divisors is an integer number (5767503).

Almost surely, 2^21422141 is an apocalyptic number.

It is an amenable number.

21422141 is a deficient number, since it is larger than the sum of its proper divisors (1647871).

21422141 is a wasteful number, since it uses less digits than its factorization.

21422141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1647870.

The product of its digits is 128, while the sum is 17.

The square root of 21422141 is about 4628.4058810783. The cubic root of 21422141 is about 277.7288256790.

Adding to 21422141 its reverse (14122412), we get a palindrome (35544553).

The spelling of 21422141 in words is "twenty-one million, four hundred twenty-two thousand, one hundred forty-one".