1301221906 has 4 divisors (see below), whose sum is σ = 1951832862. Its totient is φ = 650610952.

The previous prime is 1301221903. The next prime is 1301221913. The reversal of 1301221906 is 6091221031.

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., 707081281 + 594140625 = 26591^2 + 24375^2 .

It is not an unprimeable number, because it can be changed into a prime (1301221903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325305475 + ... + 325305478.

Almost surely, 2^1301221906 is an apocalyptic number.

1301221906 is a deficient number, since it is larger than the sum of its proper divisors (650610956).

1301221906 is an equidigital number, since it uses as much as digits as its factorization.

1301221906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 650610955.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 1301221906 is about 36072.4535622405. The cubic root of 1301221906 is about 1091.7347194476.

Adding to 1301221906 its reverse (6091221031), we get a palindrome (7392442937).

The spelling of 1301221906 in words is "one billion, three hundred one million, two hundred twenty-one thousand, nine hundred six".