1221091300900 has 27 divisors (see below), whose sum is σ = 2649792102321. Its totient is φ = 488432100240.

The previous prime is 1221091300873. The next prime is 1221091300903. The reversal of 1221091300900 is 90031901221.

The square root of 1221091300900 is 1105030.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 439592868324 + 781498432576 = 663018^2 + 884024^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221091300903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10995049 + ... + 11105551.

Almost surely, 2^{1221091300900} is an apocalyptic number.

1221091300900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221091300900 is the 1105030-th square number.

It is an amenable number.

1221091300900 is an abundant number, since it is smaller than the sum of its proper divisors (1428700801421).

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

1221091300900 is an frugal number, since it uses more digits than its factorization.

1221091300900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221020 (or 110510 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 28.

The spelling of 1221091300900 in words is "one trillion, two hundred twenty-one billion, ninety-one million, three hundred thousand, nine hundred".