21221355251155 has 8 divisors (see below), whose sum is σ = 25469862841584. Its totient is φ = 16974259840800.

The previous prime is 21221355251119. The next prime is 21221355251183. The reversal of 21221355251155 is 55115255312212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21221355251155 - 2¹⁵ = 21221355218387 is a prime.

It is a Duffinian 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, 353011956 + ... + 353072065.

It is an arithmetic number, because the mean of its divisors is an integer number (3183732855198).

Almost surely, 2^{21221355251155} is an apocalyptic number.

21221355251155 is a deficient number, since it is larger than the sum of its proper divisors (4248507590429).

21221355251155 is an equidigital number, since it uses as much as digits as its factorization.

21221355251155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706090037.

The product of its digits is 150000, while the sum is 40.

The spelling of 21221355251155 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred fifty-five million, two hundred fifty-one thousand, one hundred fifty-five".