1211111010 has 96 divisors (see below), whose sum is σ = 3246077952. Its totient is φ = 313061760.

The previous prime is 1211110987. The next prime is 1211111029. The reversal of 1211111010 is 101111121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1211110983 and 1211111001.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1221615 + ... + 1222605.

It is an arithmetic number, because the mean of its divisors is an integer number (33813312).

Almost surely, 2^1211111010 is an apocalyptic number.

1211111010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211111010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1623038976).

1211111010 is an abundant number, since it is smaller than the sum of its proper divisors (2034966942).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211111010 is a wasteful number, since it uses less digits than its factorization.

1211111010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408 (or 1405 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

The square root of 1211111010 is about 34801.0202436653. The cubic root of 1211111010 is about 1065.9282787994.

Adding to 1211111010 its reverse (101111121), we get a palindrome (1312222131).

The spelling of 1211111010 in words is "one billion, two hundred eleven million, one hundred eleven thousand, ten".