1221321029990 has 32 divisors (see below), whose sum is σ = 2314347171840. Its totient is φ = 462763346400.

The previous prime is 1221321029987. The next prime is 1221321030049. The reversal of 1221321029990 is 999201231221.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 1313945 + ... + 2041835.

It is an arithmetic number, because the mean of its divisors is an integer number (72323349120).

Almost surely, 2^{1221321029990} is an apocalyptic number.

1221321029990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221321029990 is a deficient number, since it is larger than the sum of its proper divisors (1093026141850).

1221321029990 is a wasteful number, since it uses less digits than its factorization.

1221321029990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736748.

The product of its (nonzero) digits is 34992, while the sum is 41.

The spelling of 1221321029990 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, twenty-nine thousand, nine hundred ninety".