1621438140 has 192 divisors, whose sum is σ = 5399654400. Its totient is φ = 355697664.

The previous prime is 1621438139. The next prime is 1621438157. The reversal of 1621438140 is 418341261.

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

It is a junction number, because it is equal to n+sod(n) for n = 1621438098 and 1621438107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2910742 + ... + 2911298.

It is an arithmetic number, because the mean of its divisors is an integer number (28123200).

Almost surely, 2^1621438140 is an apocalyptic number.

1621438140 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 1621438140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2699827200).

1621438140 is an abundant number, since it is smaller than the sum of its proper divisors (3778216260).

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

1621438140 is a wasteful number, since it uses less digits than its factorization.

1621438140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844 (or 842 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 1621438140 is about 40267.0850695702. The cubic root of 1621438140 is about 1174.8077283099.

The spelling of 1621438140 in words is "one billion, six hundred twenty-one million, four hundred thirty-eight thousand, one hundred forty".