21123242222 has 4 divisors (see below), whose sum is σ = 31684863336. Its totient is φ = 10561621110.

The previous prime is 21123242219. The next prime is 21123242233. The reversal of 21123242222 is 22224232112.

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

It is a super-3 number, since 3×21123242222³ (a number of 32 digits) contains 333 as substring.

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, 5280810554 + ... + 5280810557.

It is an arithmetic number, because the mean of its divisors is an integer number (7921215834).

Almost surely, 2^21123242222 is an apocalyptic number.

21123242222 is a deficient number, since it is larger than the sum of its proper divisors (10561621114).

21123242222 is a wasteful number, since it uses less digits than its factorization.

21123242222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10561621113.

The product of its digits is 1536, while the sum is 23.

Adding to 21123242222 its reverse (22224232112), we get a palindrome (43347474334).

The spelling of 21123242222 in words is "twenty-one billion, one hundred twenty-three million, two hundred forty-two thousand, two hundred twenty-two".