1221010101010 has 96 divisors (see below), whose sum is σ = 2562480431280. Its totient is φ = 417678041088.

The previous prime is 1221010100987. The next prime is 1221010101029. The reversal of 1221010101010 is 101010101221.

It can be written as a sum of positive squares in 8 ways, for example, as 954112843369 + 266897257641 = 976787^2 + 516621^2 .

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

1221010101010 is a modest number, since divided by 10101010 gives 12210 as remainder.

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, 646378146 + ... + 646380034.

Almost surely, 2^{1221010101010} is an apocalyptic number.

1221010101010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221010101010 is an abundant number, since it is smaller than the sum of its proper divisors (1341470330270).

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

1221010101010 is a wasteful number, since it uses less digits than its factorization.

1221010101010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4220 (or 4213 counting only the distinct ones).

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

Adding to 1221010101010 its reverse (101010101221), we get a palindrome (1322020202231).

The spelling of 1221010101010 in words is "one trillion, two hundred twenty-one billion, ten million, one hundred one thousand, ten".