1689400440 has 576 divisors, whose sum is σ = 7058469600. Its totient is φ = 347203584.

The previous prime is 1689400411. The next prime is 1689400441. The reversal of 1689400440 is 440049861.

It is a happy number.

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 = 1689400395 and 1689400404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1689400441) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 12153891 + ... + 12154029.

Almost surely, 2^1689400440 is an apocalyptic number.

1689400440 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 1689400440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3529234800).

1689400440 is an abundant number, since it is smaller than the sum of its proper divisors (5369069160).

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

1689400440 is a wasteful number, since it uses less digits than its factorization.

1689400440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 222 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1689400440 is about 41102.3167230267. The cubic root of 1689400440 is about 1190.9975487813.

The spelling of 1689400440 in words is "one billion, six hundred eighty-nine million, four hundred thousand, four hundred forty".