1000561000 has 64 divisors (see below), whose sum is σ = 2356595280. Its totient is φ = 397612800.

The previous prime is 1000560983. The next prime is 1000561021. The reversal of 1000561000 is 1650001.

It can be written as a sum of positive squares in 8 ways, for example, as 61873956 + 938687044 = 7866^2 + 30638^2 .

It is a super-2 number, since 2×1000561000² = 2002244629442000000, which contains 22 as substring.

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, 153814 + ... + 160186.

Almost surely, 2^1000561000 is an apocalyptic number.

1000561000 is a gapful number since it is divisible by the number (10) 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 1000561000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1178297640).

1000561000 is an abundant number, since it is smaller than the sum of its proper divisors (1356034280).

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

1000561000 is a wasteful number, since it uses less digits than its factorization.

1000561000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6551 (or 6537 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 1000561000 is about 31631.6455468254. The cubic root of 1000561000 is about 1000.1869650419.

The spelling of 1000561000 in words is "one billion, five hundred sixty-one thousand".