21121321055546 has 16 divisors (see below), whose sum is σ = 32083442202240. Its totient is φ = 10426843845600.

The previous prime is 21121321055537. The next prime is 21121321055551. The reversal of 21121321055546 is 64555012312112.

It is a super-2 number, since 2×21121321055546² (a number of 27 digits) contains 22 as substring.

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, 11711990 + ... + 13394526.

It is an arithmetic number, because the mean of its divisors is an integer number (2005215137640).

Almost surely, 2^{21121321055546} is an apocalyptic number.

21121321055546 is a deficient number, since it is larger than the sum of its proper divisors (10962121146694).

21121321055546 is a wasteful number, since it uses less digits than its factorization.

21121321055546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762069.

The product of its (nonzero) digits is 72000, while the sum is 38.

Adding to 21121321055546 its reverse (64555012312112), we get a palindrome (85676333367658).

The spelling of 21121321055546 in words is "twenty-one trillion, one hundred twenty-one billion, three hundred twenty-one million, fifty-five thousand, five hundred forty-six".