1621815809240 has 48 divisors (see below), whose sum is σ = 4010978366640. Its totient is φ = 589751201600.

The previous prime is 1621815809197. The next prime is 1621815809249. The reversal of 1621815809240 is 429085181261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621815809249) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 167538116 + ... + 167547795.

It is an arithmetic number, because the mean of its divisors is an integer number (83562049305).

Almost surely, 2^{1621815809240} is an apocalyptic number.

1621815809240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621815809240 is an abundant number, since it is smaller than the sum of its proper divisors (2389162557400).

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

1621815809240 is a wasteful number, since it uses less digits than its factorization.

1621815809240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335085944 (or 335085929 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 47.

The spelling of 1621815809240 in words is "one trillion, six hundred twenty-one billion, eight hundred fifteen million, eight hundred nine thousand, two hundred forty".