646556742000 has 800 divisors, whose sum is σ = 2525289871104. Its totient is φ = 158505984000.

The previous prime is 646556741989. The next prime is 646556742037. The reversal of 646556742000 is 247655646.

646556742000 is a `hidden beast` number, since 6 + 4 + 6 + 556 + 74 + 20 + 0 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 709721545 + ... + 709722455.

Almost surely, 2^646556742000 is an apocalyptic number.

646556742000 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 646556742000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1262644935552).

646556742000 is an abundant number, since it is smaller than the sum of its proper divisors (1878733129104).

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

646556742000 is a wasteful number, since it uses less digits than its factorization.

646556742000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1296 (or 1271 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 45.

The spelling of 646556742000 in words is "six hundred forty-six billion, five hundred fifty-six million, seven hundred forty-two thousand".