1906821440 has 224 divisors, whose sum is σ = 4977262080. Its totient is φ = 693862400.

The previous prime is 1906821431. The next prime is 1906821457. The reversal of 1906821440 is 441286091.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1906821440.

It is a congruent 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, 21424916 + ... + 21425004.

It is an arithmetic number, because the mean of its divisors is an integer number (22219920).

Almost surely, 2^1906821440 is an apocalyptic number.

1906821440 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 1906821440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2488631040).

1906821440 is an abundant number, since it is smaller than the sum of its proper divisors (3070440640).

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

1906821440 is a wasteful number, since it uses less digits than its factorization.

1906821440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 1906821440 is about 43667.1666129141. The cubic root of 1906821440 is about 1240.0428011588.

The spelling of 1906821440 in words is "one billion, nine hundred six million, eight hundred twenty-one thousand, four hundred forty".