1211220401 has 8 divisors (see below), whose sum is σ = 1243904424. Its totient is φ = 1178686080.

The previous prime is 1211220397. The next prime is 1211220427. The reversal of 1211220401 is 1040221121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 51136801 + 1160083600 = 7151^2 + 34060^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1211220401 - 2² = 1211220397 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1211220701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20930 + ... + 53483.

It is an arithmetic number, because the mean of its divisors is an integer number (155488053).

Almost surely, 2^1211220401 is an apocalyptic number.

It is an amenable number.

1211220401 is a deficient number, since it is larger than the sum of its proper divisors (32684023).

1211220401 is an equidigital number, since it uses as much as digits as its factorization.

1211220401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74851.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1211220401 is about 34802.5918718707. The cubic root of 1211220401 is about 1065.9603703938.

Adding to 1211220401 its reverse (1040221121), we get a palindrome (2251441522).

The spelling of 1211220401 in words is "one billion, two hundred eleven million, two hundred twenty thousand, four hundred one".