20154221255 has 16 divisors (see below), whose sum is σ = 27648102720. Its totient is φ = 13816023552.

The previous prime is 20154221251. The next prime is 20154221257. The reversal of 20154221255 is 55212245102.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20154221255 - 2² = 20154221251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20154221251) 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, 41231 + ... + 204959.

It is an arithmetic number, because the mean of its divisors is an integer number (1728006420).

Almost surely, 2^20154221255 is an apocalyptic number.

20154221255 is a deficient number, since it is larger than the sum of its proper divisors (7493881465).

20154221255 is a wasteful number, since it uses less digits than its factorization.

20154221255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167258.

The product of its (nonzero) digits is 8000, while the sum is 29.

Adding to 20154221255 its reverse (55212245102), we get a palindrome (75366466357).

The spelling of 20154221255 in words is "twenty billion, one hundred fifty-four million, two hundred twenty-one thousand, two hundred fifty-five".