1011211012221 has 16 divisors (see below), whose sum is σ = 1394833814400. Its totient is φ = 650866442688.

The previous prime is 1011211012187. The next prime is 1011211012271. The reversal of 1011211012221 is 1222101121101.

It is a happy number.

It is not a de Polignac number, because 1011211012221 - 2⁹ = 1011211011709 is a prime.

It is a super-2 number, since 2×1011211012221² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1011211012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011211012271) 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, 1888395 + ... + 2363991.

It is an arithmetic number, because the mean of its divisors is an integer number (87177113400).

Almost surely, 2^{1011211012221} is an apocalyptic number.

It is an amenable number.

1011211012221 is a deficient number, since it is larger than the sum of its proper divisors (383622802179).

1011211012221 is a wasteful number, since it uses less digits than its factorization.

1011211012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500068.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1011211012221 its reverse (1222101121101), we get a palindrome (2233312133322).

The spelling of 1011211012221 in words is "one trillion, eleven billion, two hundred eleven million, twelve thousand, two hundred twenty-one".