646661120 has 88 divisors (see below), whose sum is σ = 1772931264. Its totient is φ = 221700096.

The previous prime is 646661117. The next prime is 646661131. The reversal of 646661120 is 21166646.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26819 + ... + 44861.

Almost surely, 2^646661120 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 646661120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (886465632).

646661120 is an abundant number, since it is smaller than the sum of its proper divisors (1126270144).

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

646661120 is a wasteful number, since it uses less digits than its factorization.

646661120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18075 (or 18057 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 646661120 is about 25429.5324376993. The cubic root of 646661120 is about 864.7533438637.

The spelling of 646661120 in words is "six hundred forty-six million, six hundred sixty-one thousand, one hundred twenty".