1691339440 has 80 divisors (see below), whose sum is σ = 4551137280. Its totient is φ = 572532480.

The previous prime is 1691339411. The next prime is 1691339453. The reversal of 1691339440 is 449331961.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1691339393 and 1691339402.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25125 + ... + 63355.

It is an arithmetic number, because the mean of its divisors is an integer number (56889216).

Almost surely, 2^1691339440 is an apocalyptic number.

1691339440 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 1691339440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2275568640).

1691339440 is an abundant number, since it is smaller than the sum of its proper divisors (2859797840).

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

1691339440 is a wasteful number, since it uses less digits than its factorization.

1691339440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38330 (or 38324 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 1691339440 is about 41125.8974370165. The cubic root of 1691339440 is about 1191.4530281816.

The spelling of 1691339440 in words is "one billion, six hundred ninety-one million, three hundred thirty-nine thousand, four hundred forty".