1211222101 has 8 divisors (see below), whose sum is σ = 1237878144. Its totient is φ = 1184603040.

The previous prime is 1211222099. The next prime is 1211222153. The reversal of 1211222101 is 1012221121.

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

It is not a de Polignac number, because 1211222101 - 2¹ = 1211222099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211222191) 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, 63121 + ... + 80041.

It is an arithmetic number, because the mean of its divisors is an integer number (154734768).

Almost surely, 2^1211222101 is an apocalyptic number.

It is an amenable number.

1211222101 is a deficient number, since it is larger than the sum of its proper divisors (26656043).

1211222101 is a wasteful number, since it uses less digits than its factorization.

1211222101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18491.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1211222101 is about 34802.6162953304. The cubic root of 1211222101 is about 1065.9608691006.

Adding to 1211222101 its reverse (1012221121), we get a palindrome (2223443222).

The spelling of 1211222101 in words is "one billion, two hundred eleven million, two hundred twenty-two thousand, one hundred one".