255221400 has 144 divisors (see below), whose sum is σ = 920465640. Its totient is φ = 58329600.

The previous prime is 255221387. The next prime is 255221413. The reversal of 255221400 is 4122552.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (255221387) and next prime (255221413).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 25060 + ... + 33740.

Almost surely, 2^255221400 is an apocalyptic number.

255221400 is a gapful number since it is divisible by the number (20) 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 255221400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (460232820).

255221400 is an abundant number, since it is smaller than the sum of its proper divisors (665244240).

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

255221400 is a wasteful number, since it uses less digits than its factorization.

255221400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8714 (or 8698 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 255221400 is about 15975.6502215090. The cubic root of 255221400 is about 634.3160428760.

Adding to 255221400 its reverse (4122552), we get a palindrome (259343952).

The spelling of 255221400 in words is "two hundred fifty-five million, two hundred twenty-one thousand, four hundred".