864667440 has 640 divisors, whose sum is σ = 3779758080. Its totient is φ = 176836608.

The previous prime is 864667421. The next prime is 864667457. The reversal of 864667440 is 44766468.

864667440 is a `hidden beast` number, since 86 + 466 + 74 + 40 = 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 127 ways as a sum of consecutive naturals, for example, 10417639 + ... + 10417721.

It is an arithmetic number, because the mean of its divisors is an integer number (5905872).

Almost surely, 2^864667440 is an apocalyptic number.

864667440 is a gapful number since it is divisible by the number (80) 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 864667440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1889879040).

864667440 is an abundant number, since it is smaller than the sum of its proper divisors (2915090640).

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

864667440 is a wasteful number, since it uses less digits than its factorization.

864667440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The square root of 864667440 is about 29405.2281065800. The cubic root of 864667440 is about 952.6858215178.

The spelling of 864667440 in words is "eight hundred sixty-four million, six hundred sixty-seven thousand, four hundred forty".