21221584355 has 16 divisors (see below), whose sum is σ = 26200074144. Its totient is φ = 16494762240.

The previous prime is 21221584333. The next prime is 21221584361. The reversal of 21221584355 is 55348512212.

It is not a de Polignac number, because 21221584355 - 2¹⁴ = 21221567971 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 409436 + ... + 458345.

It is an arithmetic number, because the mean of its divisors is an integer number (1637504634).

Almost surely, 2^21221584355 is an apocalyptic number.

21221584355 is a deficient number, since it is larger than the sum of its proper divisors (4978489789).

21221584355 is an equidigital number, since it uses as much as digits as its factorization.

21221584355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867926.

The product of its digits is 96000, while the sum is 38.

The spelling of 21221584355 in words is "twenty-one billion, two hundred twenty-one million, five hundred eighty-four thousand, three hundred fifty-five".