21621555034206 has 16 divisors (see below), whose sum is σ = 43243401420048. Its totient is φ = 7207136452800.

The previous prime is 21621555034103. The next prime is 21621555034207. The reversal of 21621555034206 is 60243055512612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621555034207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11168935 + ... + 12961026.

It is an arithmetic number, because the mean of its divisors is an integer number (2702712588753).

Almost surely, 2^{21621555034206} is an apocalyptic number.

21621555034206 is an abundant number, since it is smaller than the sum of its proper divisors (21621846385842).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21621555034206 is a wasteful number, since it uses less digits than its factorization.

21621555034206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24279307.

The product of its (nonzero) digits is 432000, while the sum is 42.

The spelling of 21621555034206 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred fifty-five million, thirty-four thousand, two hundred six".