1213011121 has 24 divisors (see below), whose sum is σ = 1470902784. Its totient is φ = 996287040.

The previous prime is 1213011119. The next prime is 1213011133. The reversal of 1213011121 is 1211103121.

It is a happy number.

It is not a de Polignac number, because 1213011121 - 2¹ = 1213011119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213111121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 152581 + ... + 160333.

It is an arithmetic number, because the mean of its divisors is an integer number (61287616).

Almost surely, 2^1213011121 is an apocalyptic number.

It is an amenable number.

1213011121 is a deficient number, since it is larger than the sum of its proper divisors (257891663).

1213011121 is a wasteful number, since it uses less digits than its factorization.

1213011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7901 (or 7894 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1213011121 is about 34828.3091895085. The cubic root of 1213011121 is about 1066.4854321753.

Adding to 1213011121 its reverse (1211103121), we get a palindrome (2424114242).

The spelling of 1213011121 in words is "one billion, two hundred thirteen million, eleven thousand, one hundred twenty-one".