1900905840 has 320 divisors, whose sum is σ = 6929556480. Its totient is φ = 477987840.

The previous prime is 1900905823. The next prime is 1900905841. The reversal of 1900905840 is 485090091.

It is a super-2 number, since 2×1900905840² = 7226886025092211200, which contains 22 as substring.

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 = 1900905795 and 1900905804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1900905841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4123210 + ... + 4123670.

It is an arithmetic number, because the mean of its divisors is an integer number (21654864).

Almost surely, 2^1900905840 is an apocalyptic number.

1900905840 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 1900905840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3464778240).

1900905840 is an abundant number, since it is smaller than the sum of its proper divisors (5028650640).

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

1900905840 is a wasteful number, since it uses less digits than its factorization.

1900905840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 1900905840 is about 43599.3788946586. The cubic root of 1900905840 is about 1238.7591298144.

The spelling of 1900905840 in words is "one billion, nine hundred million, nine hundred five thousand, eight hundred forty".