1221232101 has 16 divisors (see below), whose sum is σ = 1691121600. Its totient is φ = 783243648.

The previous prime is 1221232099. The next prime is 1221232123. The reversal of 1221232101 is 1012321221.

It is not a de Polignac number, because 1221232101 - 2¹ = 1221232099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221232151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51931 + ... + 71688.

It is an arithmetic number, because the mean of its divisors is an integer number (105695100).

Almost surely, 2^1221232101 is an apocalyptic number.

It is an amenable number.

1221232101 is a deficient number, since it is larger than the sum of its proper divisors (469889499).

1221232101 is a wasteful number, since it uses less digits than its factorization.

1221232101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123748.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1221232101 is about 34946.1314167963. The cubic root of 1221232101 is about 1068.8893185640.

Adding to 1221232101 its reverse (1012321221), we get a palindrome (2233553322).

The spelling of 1221232101 in words is "one billion, two hundred twenty-one million, two hundred thirty-two thousand, one hundred one".