1221453215 has 8 divisors (see below), whose sum is σ = 1487621040. Its totient is φ = 962577792.

The previous prime is 1221453199. The next prime is 1221453217. The reversal of 1221453215 is 5123541221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221453215 - 2⁴ = 1221453199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221453217) 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, 1822730 + ... + 1823399.

It is an arithmetic number, because the mean of its divisors is an integer number (185952630).

Almost surely, 2^1221453215 is an apocalyptic number.

1221453215 is a deficient number, since it is larger than the sum of its proper divisors (266167825).

1221453215 is an equidigital number, since it uses as much as digits as its factorization.

1221453215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3646201.

The product of its digits is 2400, while the sum is 26.

The square root of 1221453215 is about 34949.2949142039. The cubic root of 1221453215 is about 1068.9538250379.

Adding to 1221453215 its reverse (5123541221), we get a palindrome (6344994436).

The spelling of 1221453215 in words is "one billion, two hundred twenty-one million, four hundred fifty-three thousand, two hundred fifteen".