1221010120005 has 16 divisors (see below), whose sum is σ = 2103894360960. Its totient is φ = 601112674368.

The previous prime is 1221010120003. The next prime is 1221010120007. The reversal of 1221010120005 is 5000210101221.

It is an interprime number because it is at equal distance from previous prime (1221010120003) and next prime (1221010120007).

It is not a de Polignac number, because 1221010120005 - 2¹ = 1221010120003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221010120003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3130794985 + ... + 3130795374.

It is an arithmetic number, because the mean of its divisors is an integer number (131493397560).

Almost surely, 2^{1221010120005} is an apocalyptic number.

1221010120005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221010120005 is a deficient number, since it is larger than the sum of its proper divisors (882884240955).

1221010120005 is a wasteful number, since it uses less digits than its factorization.

1221010120005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6261590380.

The product of its (nonzero) digits is 40, while the sum is 15.

Adding to 1221010120005 its reverse (5000210101221), we get a palindrome (6221220221226).

The spelling of 1221010120005 in words is "one trillion, two hundred twenty-one billion, ten million, one hundred twenty thousand, five".