155621222400 has 288 divisors, whose sum is σ = 587960493120. Its totient is φ = 35570319360.

The previous prime is 155621222357. The next prime is 155621222459. The reversal of 155621222400 is 4222126551.

It is a super-2 number, since 2×155621222400² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1002832 + ... + 1147568.

It is an arithmetic number, because the mean of its divisors is an integer number (2041529490).

Almost surely, 2^155621222400 is an apocalyptic number.

155621222400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155621222400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293980246560).

155621222400 is an abundant number, since it is smaller than the sum of its proper divisors (432339270720).

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

155621222400 is a wasteful number, since it uses less digits than its factorization.

155621222400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144779 (or 144754 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 155621222400 its reverse (4222126551), we get a palindrome (159843348951).

The spelling of 155621222400 in words is "one hundred fifty-five billion, six hundred twenty-one million, two hundred twenty-two thousand, four hundred".