615664 has 40 divisors (see below), whose sum is σ = 1428480. Its totient is φ = 251328.

The previous prime is 615661. The next prime is 615677. The reversal of 615664 is 466516.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (615661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2457 + ... + 2695.

It is an arithmetic number, because the mean of its divisors is an integer number (35712).

2⁶¹⁵⁶⁶⁴ 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 615664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714240).

615664 is an abundant number, since it is smaller than the sum of its proper divisors (812816).

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

615664 is a wasteful number, since it uses less digits than its factorization.

615664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277 (or 271 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 615664 is about 784.6425937967. The cubic root of 615664 is about 85.0709442310.

The spelling of 615664 in words is "six hundred fifteen thousand, six hundred sixty-four".