664961654016 has 864 divisors, whose sum is σ = 2294188216320. Its totient is φ = 190468454400.

The previous prime is 664961653943. The next prime is 664961654017. The reversal of 664961654016 is 610456169466.

It is a happy number.

664961654016 is a `hidden beast` number, since 6 + 6 + 4 + 9 + 616 + 5 + 4 + 0 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664961654017) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 15464224491 + ... + 15464224533.

Almost surely, 2^664961654016 is an apocalyptic number.

664961654016 is a gapful number since it is divisible by the number (66) 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 664961654016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1147094108160).

664961654016 is an abundant number, since it is smaller than the sum of its proper divisors (1629226562304).

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

664961654016 is an frugal number, since it uses more digits than its factorization.

664961654016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 54.

The spelling of 664961654016 in words is "six hundred sixty-four billion, nine hundred sixty-one million, six hundred fifty-four thousand, sixteen".