1628144640 has 264 divisors, whose sum is σ = 5719236120. Its totient is φ = 428212224.

The previous prime is 1628144603. The next prime is 1628144653. The reversal of 1628144640 is 464418261.

It is a happy number.

1628144640 is a `hidden beast` number, since 1 + 6 + 2 + 8 + 1 + 4 + 4 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 94012416 + 1534132224 = 9696^2 + 39168^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1628144595 and 1628144604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4100922 + ... + 4101318.

Almost surely, 2^1628144640 is an apocalyptic number.

1628144640 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 1628144640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2859618060).

1628144640 is an abundant number, since it is smaller than the sum of its proper divisors (4091091480).

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

1628144640 is a wasteful number, since it uses less digits than its factorization.

1628144640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 496 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 1628144640 is about 40350.2743485097. The cubic root of 1628144640 is about 1176.4252245410.

The spelling of 1628144640 in words is "one billion, six hundred twenty-eight million, one hundred forty-four thousand, six hundred forty".