1221255464 has 64 divisors (see below), whose sum is σ = 2695472640. Its totient is φ = 511407360.

The previous prime is 1221255463. The next prime is 1221255467. The reversal of 1221255464 is 4645521221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221255464.

It is not an unprimeable number, because it can be changed into a prime (1221255463) 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, 986654 + ... + 987890.

It is an arithmetic number, because the mean of its divisors is an integer number (42116760).

Almost surely, 2^1221255464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221255464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1347736320).

1221255464 is an abundant number, since it is smaller than the sum of its proper divisors (1474217176).

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

1221255464 is a wasteful number, since it uses less digits than its factorization.

1221255464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2130 (or 2126 counting only the distinct ones).

The product of its digits is 19200, while the sum is 32.

The square root of 1221255464 is about 34946.4656868187. The cubic root of 1221255464 is about 1068.8961347135.

Adding to 1221255464 its reverse (4645521221), we get a palindrome (5866776685).

It can be divided in two parts, 12212 and 55464, that added together give a palindrome (67676).

The spelling of 1221255464 in words is "one billion, two hundred twenty-one million, two hundred fifty-five thousand, four hundred sixty-four".