21431422 has 4 divisors (see below), whose sum is σ = 32147136. Its totient is φ = 10715710.

The previous prime is 21431401. The next prime is 21431489. The reversal of 21431422 is 22413412.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21431422.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5357854 + ... + 5357857.

It is an arithmetic number, because the mean of its divisors is an integer number (8036784).

Almost surely, 2^21431422 is an apocalyptic number.

21431422 is a deficient number, since it is larger than the sum of its proper divisors (10715714).

21431422 is a wasteful number, since it uses less digits than its factorization.

21431422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10715713.

The product of its digits is 384, while the sum is 19.

The square root of 21431422 is about 4629.4083855283. The cubic root of 21431422 is about 277.7689279432.

Adding to 21431422 its reverse (22413412), we get a palindrome (43844834).

The spelling of 21431422 in words is "twenty-one million, four hundred thirty-one thousand, four hundred twenty-two".