1221143245 has 32 divisors (see below), whose sum is σ = 1692182016. Its totient is φ = 828672000.

The previous prime is 1221143239. The next prime is 1221143251. The reversal of 1221143245 is 5423411221.

It is an interprime number because it is at equal distance from previous prime (1221143239) and next prime (1221143251).

It is not a de Polignac number, because 1221143245 - 2⁹ = 1221142733 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2343585 + ... + 2344105.

It is an arithmetic number, because the mean of its divisors is an integer number (52880688).

Almost surely, 2^1221143245 is an apocalyptic number.

It is an amenable number.

1221143245 is a deficient number, since it is larger than the sum of its proper divisors (471038771).

1221143245 is a wasteful number, since it uses less digits than its factorization.

1221143245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101.

The product of its digits is 1920, while the sum is 25.

The square root of 1221143245 is about 34944.8600655375. The cubic root of 1221143245 is about 1068.8633940536.

Adding to 1221143245 its reverse (5423411221), we get a palindrome (6644554466).

The spelling of 1221143245 in words is "one billion, two hundred twenty-one million, one hundred forty-three thousand, two hundred forty-five".