21542222 has 8 divisors (see below), whose sum is σ = 34799016. Its totient is φ = 9942552.

The previous prime is 21542173. The next prime is 21542231. The reversal of 21542222 is 22224512.

It is a sphenic number, since it is the product of 3 distinct primes.

21542222 is a modest number, since divided by 2222 gives 2154 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21542194 and 21542203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 414248 + ... + 414299.

It is an arithmetic number, because the mean of its divisors is an integer number (4349877).

Almost surely, 2^21542222 is an apocalyptic number.

21542222 is a deficient number, since it is larger than the sum of its proper divisors (13256794).

21542222 is a wasteful number, since it uses less digits than its factorization.

21542222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828562.

The product of its digits is 640, while the sum is 20.

The square root of 21542222 is about 4641.3599300205. The cubic root of 21542222 is about 278.2467918723.

Adding to 21542222 its reverse (22224512), we get a palindrome (43766734).

The spelling of 21542222 in words is "twenty-one million, five hundred forty-two thousand, two hundred twenty-two".