667964561940 has 384 divisors, whose sum is σ = 2300513402880. Its totient is φ = 159861993984.

The previous prime is 667964561843. The next prime is 667964561947. The reversal of 667964561940 is 49165469766.

667964561940 is a `hidden beast` number, since 6 + 6 + 7 + 9 + 6 + 4 + 5 + 619 + 4 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667964561947) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 67309819 + ... + 67319741.

It is an arithmetic number, because the mean of its divisors is an integer number (5990920320).

Almost surely, 2^667964561940 is an apocalyptic number.

667964561940 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 667964561940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150256701440).

667964561940 is an abundant number, since it is smaller than the sum of its proper divisors (1632548840940).

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

667964561940 is a wasteful number, since it uses less digits than its factorization.

667964561940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10220 (or 10212 counting only the distinct ones).

The product of its (nonzero) digits is 58786560, while the sum is 63.

The spelling of 667964561940 in words is "six hundred sixty-seven billion, nine hundred sixty-four million, five hundred sixty-one thousand, nine hundred forty".