1628921880 has 128 divisors (see below), whose sum is σ = 5617080000. Its totient is φ = 419392512.

The previous prime is 1628921867. The next prime is 1628921887. The reversal of 1628921880 is 881298261.

It is a happy number.

1628921880 is a `hidden beast` number, since 1 + 628 + 9 + 2 + 18 + 8 + 0 = 666.

It is a super-2 number, since 2×1628921880² = 5306772982285468800, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1628921887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5316 + ... + 57324.

Almost surely, 2^1628921880 is an apocalyptic number.

1628921880 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 1628921880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2808540000).

1628921880 is an abundant number, since it is smaller than the sum of its proper divisors (3988158120).

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

1628921880 is a wasteful number, since it uses less digits than its factorization.

1628921880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52058 (or 52048 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 1628921880 is about 40359.9043606399. The cubic root of 1628921880 is about 1176.6123944968.

The spelling of 1628921880 in words is "one billion, six hundred twenty-eight million, nine hundred twenty-one thousand, eight hundred eighty".