21521042422 has 16 divisors (see below), whose sum is σ = 35317170000. Its totient is φ = 9754259040.

The previous prime is 21521042401. The next prime is 21521042453. The reversal of 21521042422 is 22424012512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1393797 + ... + 1409152.

It is an arithmetic number, because the mean of its divisors is an integer number (2207323125).

Almost surely, 2^21521042422 is an apocalyptic number.

21521042422 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21521042422 is a deficient number, since it is larger than the sum of its proper divisors (13796127578).

21521042422 is a wasteful number, since it uses less digits than its factorization.

21521042422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2803311.

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21521042422 its reverse (22424012512), we get a palindrome (43945054934).

The spelling of 21521042422 in words is "twenty-one billion, five hundred twenty-one million, forty-two thousand, four hundred twenty-two".