1211621062400 has 1728 divisors, whose sum is σ = 4105257246720. Its totient is φ = 343985356800.

The previous prime is 1211621062397. The next prime is 1211621062433. The reversal of 1211621062400 is 42601261121.

It is a harmonic number, since the harmonic mean of its divisors is an integer.

It is a self number, because there is not a number n which added to its sum of digits gives 1211621062400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 16597548764 + ... + 16597548836.

Almost surely, 2^{1211621062400} is an apocalyptic number.

1211621062400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211621062400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2052628623360).

1211621062400 is an abundant number, since it is smaller than the sum of its proper divisors (2893636184320).

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

1211621062400 is a wasteful number, since it uses less digits than its factorization.

1211621062400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The spelling of 1211621062400 in words is "one trillion, two hundred eleven billion, six hundred twenty-one million, sixty-two thousand, four hundred".