64400670 has 80 divisors (see below), whose sum is σ = 177289200. Its totient is φ = 16774128.

The previous prime is 64400663. The next prime is 64400717. The reversal of 64400670 is 7600446.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1497669 + ... + 1497711.

It is an arithmetic number, because the mean of its divisors is an integer number (2216115).

Almost surely, 2^64400670 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64400670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88644600).

64400670 is an abundant number, since it is smaller than the sum of its proper divisors (112888530).

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

64400670 is an frugal number, since it uses more digits than its factorization.

64400670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 64400670 is about 8025.0028037378. The cubic root of 64400670 is about 400.8329932680.

The spelling of 64400670 in words is "sixty-four million, four hundred thousand, six hundred seventy".