645556050 has 72 divisors (see below), whose sum is σ = 1743614964. Its totient is φ = 171233280.

The previous prime is 645556039. The next prime is 645556061. The reversal of 645556050 is 50655546.

It is a happy number.

645556050 is a `hidden beast` number, since 6 + 45 + 5 + 5 + 605 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (645556039) and next prime (645556061).

It can be written as a sum of positive squares in 6 ways, for example, as 36108081 + 609447969 = 6009^2 + 24687^2 .

It is a super-2 number, since 2×645556050² = 833485227383205000, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645555996 and 645556014.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 83134 + ... + 90566.

Almost surely, 2^645556050 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645556050, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (871807482).

645556050 is an abundant number, since it is smaller than the sum of its proper divisors (1098058914).

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

645556050 is a wasteful number, since it uses less digits than its factorization.

645556050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7644 (or 7636 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The square root of 645556050 is about 25407.7950637201. The cubic root of 645556050 is about 864.2604747704.

The spelling of 645556050 in words is "six hundred forty-five million, five hundred fifty-six thousand, fifty".