1621645284 has 96 divisors (see below), whose sum is σ = 4445392896. Its totient is φ = 450443520.

The previous prime is 1621645261. The next prime is 1621645303. The reversal of 1621645284 is 4825461261.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1263307 + ... + 1264589.

It is an arithmetic number, because the mean of its divisors is an integer number (46306176).

Almost surely, 2^1621645284 is an apocalyptic number.

1621645284 is a gapful number since it is divisible by the number (14) 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 1621645284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2222696448).

1621645284 is an abundant number, since it is smaller than the sum of its proper divisors (2823747612).

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

1621645284 is a wasteful number, since it uses less digits than its factorization.

1621645284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1705 (or 1703 counting only the distinct ones).

The product of its digits is 92160, while the sum is 39.

The square root of 1621645284 is about 40269.6571130175. The cubic root of 1621645284 is about 1174.8577546833.

The spelling of 1621645284 in words is "one billion, six hundred twenty-one million, six hundred forty-five thousand, two hundred eighty-four".