645775104 has 144 divisors (see below), whose sum is σ = 1879041024. Its totient is φ = 195686400.

The previous prime is 645775087. The next prime is 645775121. The reversal of 645775104 is 401577546.

It is an interprime number because it is at equal distance from previous prime (645775087) and next prime (645775121).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 708409 + ... + 709319.

It is an arithmetic number, because the mean of its divisors is an integer number (13048896).

Almost surely, 2^645775104 is an apocalyptic number.

645775104 is a gapful number since it is divisible by the number (64) 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 645775104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (939520512).

645775104 is an abundant number, since it is smaller than the sum of its proper divisors (1233265920).

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

645775104 is a wasteful number, since it uses less digits than its factorization.

645775104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014 (or 1000 counting only the distinct ones).

The product of its (nonzero) digits is 117600, while the sum is 39.

The square root of 645775104 is about 25412.1054617676. The cubic root of 645775104 is about 864.3582190868.

The spelling of 645775104 in words is "six hundred forty-five million, seven hundred seventy-five thousand, one hundred four".