1221100121070 has 64 divisors (see below), whose sum is σ = 3281124084480. Its totient is φ = 323140989600.

The previous prime is 1221100120979. The next prime is 1221100121071. The reversal of 1221100121070 is 701210011221.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221100121071) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17226436 + ... + 17297175.

It is an arithmetic number, because the mean of its divisors is an integer number (51267563820).

Almost surely, 2^{1221100121070} is an apocalyptic number.

1221100121070 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221100121070 is an abundant number, since it is smaller than the sum of its proper divisors (2060023963410).

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

1221100121070 is a wasteful number, since it uses less digits than its factorization.

1221100121070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34523758 (or 34523752 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 18.

Adding to 1221100121070 its reverse (701210011221), we get a palindrome (1922310132291).

The spelling of 1221100121070 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred twenty-one thousand, seventy".