1221401242 has 4 divisors (see below), whose sum is σ = 1832101866. Its totient is φ = 610700620.

The previous prime is 1221401239. The next prime is 1221401243. The reversal of 1221401242 is 2421041221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 992817081 + 228584161 = 31509^2 + 15119^2 .

It is not an unprimeable number, because it can be changed into a prime (1221401243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305350309 + ... + 305350312.

Almost surely, 2^1221401242 is an apocalyptic number.

1221401242 is a deficient number, since it is larger than the sum of its proper divisors (610700624).

1221401242 is an equidigital number, since it uses as much as digits as its factorization.

1221401242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610700623.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 1221401242 is about 34948.5513576743. The cubic root of 1221401242 is about 1068.9386634461.

Adding to 1221401242 its reverse (2421041221), we get a palindrome (3642442463).

The spelling of 1221401242 in words is "one billion, two hundred twenty-one million, four hundred one thousand, two hundred forty-two".