1221020010099 has 16 divisors (see below), whose sum is σ = 1813691420800. Its totient is φ = 811865540808.

The previous prime is 1221020010073. The next prime is 1221020010103. The reversal of 1221020010099 is 9900100201221.

It is not a de Polignac number, because 1221020010099 - 2¹⁹ = 1221019485811 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221020010499) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59650669 + ... + 59671134.

It is an arithmetic number, because the mean of its divisors is an integer number (113355713800).

Almost surely, 2^{1221020010099} is an apocalyptic number.

1221020010099 is a deficient number, since it is larger than the sum of its proper divisors (592671410701).

1221020010099 is a wasteful number, since it uses less digits than its factorization.

1221020010099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119322191 (or 119322185 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The spelling of 1221020010099 in words is "one trillion, two hundred twenty-one billion, twenty million, ten thousand, ninety-nine".