1621542349440 has 1536 divisors, whose sum is σ = 6495914880000. Its totient is φ = 369689886720.

The previous prime is 1621542349433. The next prime is 1621542349501. The reversal of 1621542349440 is 449432451261.

1621542349440 is a `hidden beast` number, since 1 + 6 + 2 + 154 + 2 + 3 + 494 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 10882834486 + ... + 10882834634.

It is an arithmetic number, because the mean of its divisors is an integer number (4229111250).

Almost surely, 2^{1621542349440} is an apocalyptic number.

1621542349440 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 1621542349440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3247957440000).

1621542349440 is an abundant number, since it is smaller than the sum of its proper divisors (4874372530560).

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

1621542349440 is a wasteful number, since it uses less digits than its factorization.

1621542349440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370 (or 355 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 1621542349440 in words is "one trillion, six hundred twenty-one billion, five hundred forty-two million, three hundred forty-nine thousand, four hundred forty".