1221100101010 has 32 divisors (see below), whose sum is σ = 2220796760112. Its totient is φ = 483374284800.

The previous prime is 1221100100977. The next prime is 1221100101031. The reversal of 1221100101010 is 101010011221.

It can be written as a sum of positive squares in 8 ways, for example, as 188419369329 + 1032680731681 = 434073^2 + 1016209^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1848042 + ... + 2420218.

Almost surely, 2^{1221100101010} is an apocalyptic number.

1221100101010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221100101010 is a deficient number, since it is larger than the sum of its proper divisors (999696659102).

1221100101010 is a wasteful number, since it uses less digits than its factorization.

1221100101010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574398.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 1221100101010 its reverse (101010011221), we get a palindrome (1322110112231).

The spelling of 1221100101010 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred one thousand, ten".