21221365123126 has 64 divisors (see below), whose sum is σ = 38546216755200. Its totient is φ = 8553933448704.

The previous prime is 21221365123103. The next prime is 21221365123151. The reversal of 21221365123126 is 62132156312212.

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 31 ways as a sum of consecutive naturals, for example, 3609686655 + ... + 3609692533.

It is an arithmetic number, because the mean of its divisors is an integer number (602284636800).

Almost surely, 2^{21221365123126} is an apocalyptic number.

21221365123126 is a deficient number, since it is larger than the sum of its proper divisors (17324851632074).

21221365123126 is a wasteful number, since it uses less digits than its factorization.

21221365123126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13861.

The product of its digits is 51840, while the sum is 37.

The spelling of 21221365123126 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred sixty-five million, one hundred twenty-three thousand, one hundred twenty-six".