665474940 has 168 divisors, whose sum is σ = 2257106208. Its totient is φ = 163762560.

The previous prime is 665474881. The next prime is 665474941. The reversal of 665474940 is 49474566.

665474940 is a `hidden beast` number, since 66 + 547 + 4 + 9 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665474941) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 187785 + ... + 191295.

It is an arithmetic number, because the mean of its divisors is an integer number (13435156).

Almost surely, 2^665474940 is an apocalyptic number.

665474940 is a gapful number since it is divisible by the number (60) 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 665474940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1128553104).

665474940 is an abundant number, since it is smaller than the sum of its proper divisors (1591631268).

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

665474940 is a wasteful number, since it uses less digits than its factorization.

665474940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3551 (or 3534 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 665474940 is about 25796.8009644607. The cubic root of 665474940 is about 873.0596196928.

The spelling of 665474940 in words is "six hundred sixty-five million, four hundred seventy-four thousand, nine hundred forty".