1691905440 has 96 divisors (see below), whose sum is σ = 5409149760. Its totient is φ = 444432384.

The previous prime is 1691905429. The next prime is 1691905441. The reversal of 1691905440 is 445091961.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (1691905441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5856 + ... + 58464.

It is an arithmetic number, because the mean of its divisors is an integer number (56345310).

Almost surely, 2^1691905440 is an apocalyptic number.

1691905440 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 1691905440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2704574880).

1691905440 is an abundant number, since it is smaller than the sum of its proper divisors (3717244320).

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

1691905440 is a wasteful number, since it uses less digits than its factorization.

1691905440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52694 (or 52686 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 1691905440 is about 41132.7781702136. The cubic root of 1691905440 is about 1191.5859183607.

The spelling of 1691905440 in words is "one billion, six hundred ninety-one million, nine hundred five thousand, four hundred forty".