21621214 has 4 divisors (see below), whose sum is σ = 32431824. Its totient is φ = 10810606.

The previous prime is 21621181. The next prime is 21621233. The reversal of 21621214 is 41212612.

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

It is a junction number, because it is equal to n+sod(n) for n = 21621191 and 21621200.

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, 5405302 + ... + 5405305.

It is an arithmetic number, because the mean of its divisors is an integer number (8107956).

Almost surely, 2^21621214 is an apocalyptic number.

21621214 is a deficient number, since it is larger than the sum of its proper divisors (10810610).

21621214 is a wasteful number, since it uses less digits than its factorization.

21621214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10810609.

The product of its digits is 192, while the sum is 19.

The square root of 21621214 is about 4649.8617183740. The cubic root of 21621214 is about 278.5864730236.

Adding to 21621214 its reverse (41212612), we get a palindrome (62833826).

The spelling of 21621214 in words is "twenty-one million, six hundred twenty-one thousand, two hundred fourteen".