1221001101010 has 128 divisors (see below), whose sum is σ = 2299048012800. Its totient is φ = 466562764800.

The previous prime is 1221001100987. The next prime is 1221001101011. The reversal of 1221001101010 is 101011001221.

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

It is not an unprimeable number, because it can be changed into a prime (1221001101011) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2648592180 + ... + 2648592640.

It is an arithmetic number, because the mean of its divisors is an integer number (17961312600).

Almost surely, 2^{1221001101010} is an apocalyptic number.

1221001101010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221001101010 is a deficient number, since it is larger than the sum of its proper divisors (1078046911790).

1221001101010 is a wasteful number, since it uses less digits than its factorization.

1221001101010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1172.

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

Adding to 1221001101010 its reverse (101011001221), we get a palindrome (1322012102231).

The spelling of 1221001101010 in words is "one trillion, two hundred twenty-one billion, one million, one hundred one thousand, ten".