1665423340 has 96 divisors (see below), whose sum is σ = 4249728000. Its totient is φ = 535507200.

The previous prime is 1665423313. The next prime is 1665423341. The reversal of 1665423340 is 433245661.

It is a junction number, because it is equal to n+sod(n) for n = 1665423296 and 1665423305.

It is not an unprimeable number, because it can be changed into a prime (1665423341) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 265561 + ... + 271759.

It is an arithmetic number, because the mean of its divisors is an integer number (44268000).

Almost surely, 2^1665423340 is an apocalyptic number.

1665423340 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 1665423340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2124864000).

1665423340 is an abundant number, since it is smaller than the sum of its proper divisors (2584304660).

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

1665423340 is a wasteful number, since it uses less digits than its factorization.

1665423340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6335 (or 6333 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 34.

The square root of 1665423340 is about 40809.5986258135. The cubic root of 1665423340 is about 1185.3362028004.

The spelling of 1665423340 in words is "one billion, six hundred sixty-five million, four hundred twenty-three thousand, three hundred forty".