1221530642 has 8 divisors (see below), whose sum is σ = 1834431600. Its totient is φ = 610053444.

The previous prime is 1221530641. The next prime is 1221530677. The reversal of 1221530642 is 2460351221.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (1221530641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353792 + ... + 357227.

It is an arithmetic number, because the mean of its divisors is an integer number (229303950).

Almost surely, 2^1221530642 is an apocalyptic number.

1221530642 is a deficient number, since it is larger than the sum of its proper divisors (612900958).

1221530642 is an equidigital number, since it uses as much as digits as its factorization.

1221530642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711880.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 1221530642 is about 34950.4026014007. The cubic root of 1221530642 is about 1068.9764112868.

Adding to 1221530642 its reverse (2460351221), we get a palindrome (3681881863).

The spelling of 1221530642 in words is "one billion, two hundred twenty-one million, five hundred thirty thousand, six hundred forty-two".