1621261650000 has 240 divisors, whose sum is σ = 5238180360000. Its totient is φ = 432072960000.

The previous prime is 1621261649989. The next prime is 1621261650059. The reversal of 1621261650000 is 561621261.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 1621261650000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 463348251 + ... + 463351749.

It is an arithmetic number, because the mean of its divisors is an integer number (21825751500).

Almost surely, 2^{1621261650000} is an apocalyptic number.

1621261650000 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 1621261650000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2619090180000).

1621261650000 is an abundant number, since it is smaller than the sum of its proper divisors (3616918710000).

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

1621261650000 is an equidigital number, since it uses as much as digits as its factorization.

1621261650000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6624 (or 6598 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The spelling of 1621261650000 in words is "one trillion, six hundred twenty-one billion, two hundred sixty-one million, six hundred fifty thousand".