21533351331355 has 16 divisors (see below), whose sum is σ = 26623733108544. Its totient is φ = 16707200849280.

The previous prime is 21533351331353. The next prime is 21533351331367. The reversal of 21533351331355 is 55313315333512.

It is not a de Polignac number, because 21533351331355 - 2¹ = 21533351331353 is a prime.

It is a super-2 number, since 2×21533351331355² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21533351331353) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 187075092 + ... + 187190161.

It is an arithmetic number, because the mean of its divisors is an integer number (1663983319284).

Almost surely, 2^{21533351331355} is an apocalyptic number.

21533351331355 is a deficient number, since it is larger than the sum of its proper divisors (5090381777189).

21533351331355 is a wasteful number, since it uses less digits than its factorization.

21533351331355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374265606.

The product of its digits is 911250, while the sum is 43.

Adding to 21533351331355 its reverse (55313315333512), we get a palindrome (76846666664867).

The spelling of 21533351331355 in words is "twenty-one trillion, five hundred thirty-three billion, three hundred fifty-one million, three hundred thirty-one thousand, three hundred fifty-five".