1620651939840 has 240 divisors, whose sum is σ = 5808921758640. Its totient is φ = 432173629440.

The previous prime is 1620651939793. The next prime is 1620651939853. The reversal of 1620651939840 is 489391560261.

1620651939840 is a `hidden beast` number, since 1 + 6 + 206 + 5 + 1 + 9 + 398 + 40 = 666.

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 (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 147516 + ... + 1806395.

It is an arithmetic number, because the mean of its divisors is an integer number (24203840661).

Almost surely, 2^{1620651939840} is an apocalyptic number.

1620651939840 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 1620651939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2904460879320).

1620651939840 is an abundant number, since it is smaller than the sum of its proper divisors (4188269818800).

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

1620651939840 is an equidigital number, since it uses as much as digits as its factorization.

1620651939840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1953950 (or 1953921 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The spelling of 1620651939840 in words is "one trillion, six hundred twenty billion, six hundred fifty-one million, nine hundred thirty-nine thousand, eight hundred forty".