1255213221 has 8 divisors (see below), whose sum is σ = 1676152224. Its totient is φ = 835541520.

The previous prime is 1255213217. The next prime is 1255213243. The reversal of 1255213221 is 1223125521.

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

It is not a de Polignac number, because 1255213221 - 2² = 1255213217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1255213191 and 1255213200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1255213261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 314511 + ... + 318476.

It is an arithmetic number, because the mean of its divisors is an integer number (209519028).

Almost surely, 2^1255213221 is an apocalyptic number.

It is an amenable number.

1255213221 is a deficient number, since it is larger than the sum of its proper divisors (420939003).

1255213221 is an equidigital number, since it uses as much as digits as its factorization.

1255213221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633651.

The product of its digits is 1200, while the sum is 24.

The square root of 1255213221 is about 35428.9884275575. The cubic root of 1255213221 is about 1078.7128071813.

Adding to 1255213221 its reverse (1223125521), we get a palindrome (2478338742).

The spelling of 1255213221 in words is "one billion, two hundred fifty-five million, two hundred thirteen thousand, two hundred twenty-one".