1221016634 has 4 divisors (see below), whose sum is σ = 1831524954. Its totient is φ = 610508316.

The previous prime is 1221016633. The next prime is 1221016669. The reversal of 1221016634 is 4366101221.

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., 1211388025 + 9628609 = 34805^2 + 3103^2 .

It is not an unprimeable number, because it can be changed into a prime (1221016633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305254157 + ... + 305254160.

Almost surely, 2^1221016634 is an apocalyptic number.

1221016634 is a deficient number, since it is larger than the sum of its proper divisors (610508320).

1221016634 is an equidigital number, since it uses as much as digits as its factorization.

1221016634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610508319.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 1221016634 is about 34943.0484359908. The cubic root of 1221016634 is about 1068.8264520210.

Adding to 1221016634 its reverse (4366101221), we get a palindrome (5587117855).

The spelling of 1221016634 in words is "one billion, two hundred twenty-one million, sixteen thousand, six hundred thirty-four".