1221222101 has 4 divisors (see below), whose sum is σ = 1332242304. Its totient is φ = 1110201900.

The previous prime is 1221222089. The next prime is 1221222113. The reversal of 1221222101 is 1012221221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1221222089) and next prime (1221222113).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221222101 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221222151) 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, 55510085 + ... + 55510106.

It is an arithmetic number, because the mean of its divisors is an integer number (333060576).

Almost surely, 2^1221222101 is an apocalyptic number.

1221222101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221222101 is a deficient number, since it is larger than the sum of its proper divisors (111020203).

1221222101 is a wasteful number, since it uses less digits than its factorization.

1221222101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111020202.

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

The square root of 1221222101 is about 34945.9883391499. The cubic root of 1221222101 is about 1068.8864010398.

Adding to 1221222101 its reverse (1012221221), we get a palindrome (2233443322).

It can be divided in two parts, 1221 and 222101, that added together give a palindrome (223322).

The spelling of 1221222101 in words is "one billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred one".