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668860416 = 217367

668860416 has 252 divisors, whose sum is σ = 2292178392. Its totient is φ = 191102976.

The previous prime is 668860411. The next prime is 668860421. The reversal of 668860416 is 614068866.

It is an interprime number because it is at equal distance from previous prime (668860411) and next prime (668860421).

It is a tau number, because it is divible by the number of its divisors (252).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668860411) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 95551485 + ... + 95551491.

It is an arithmetic number, because the mean of its divisors is an integer number (9095946).

Almost surely, 2668860416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668860416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1146089196).

668860416 is an abundant number, since it is smaller than the sum of its proper divisors (1623317976).

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

668860416 is an frugal number, since it uses more digits than its factorization.

668860416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59 (or 12 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 668860416 is about 25862.3358573815. The cubic root of 668860416 is about 874.5376239002.

668860416 divided by its product of nonzero digits (331776) gives a triangular number (2016 = T63).

The spelling of 668860416 in words is "six hundred sixty-eight million, eight hundred sixty thousand, four hundred sixteen".