1201221001 has 4 divisors (see below), whose sum is σ = 1202286100. Its totient is φ = 1200155904.

The previous prime is 1201220987. The next prime is 1201221011. The reversal of 1201221001 is 1001221021.

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

It can be written as a sum of positive squares in 2 ways, for example, as 226532601 + 974688400 = 15051^2 + 31220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201221001 - 2²⁵ = 1167666569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1201221011) 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, 530856 + ... + 533113.

It is an arithmetic number, because the mean of its divisors is an integer number (300571525).

Almost surely, 2^1201221001 is an apocalyptic number.

It is an amenable number.

1201221001 is a deficient number, since it is larger than the sum of its proper divisors (1065099).

1201221001 is a wasteful number, since it uses less digits than its factorization.

1201221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065098.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1201221001 is about 34658.6353020427. The cubic root of 1201221001 is about 1063.0188656695.

Adding to 1201221001 its reverse (1001221021), we get a palindrome (2202442022).

The spelling of 1201221001 in words is "one billion, two hundred one million, two hundred twenty-one thousand, one".