1001561200 has 60 divisors (see below), whose sum is σ = 2411956240. Its totient is φ = 399674880.

The previous prime is 1001561191. The next prime is 1001561207. The reversal of 1001561200 is 21651001.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001561207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180061 + ... + 185539.

Almost surely, 2^1001561200 is an apocalyptic number.

1001561200 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 1001561200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1205978120).

1001561200 is an abundant number, since it is smaller than the sum of its proper divisors (1410395040).

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

1001561200 is a wasteful number, since it uses less digits than its factorization.

1001561200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5954 (or 5943 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 1001561200 is about 31647.4517141586. The cubic root of 1001561200 is about 1000.5201294185.

The spelling of 1001561200 in words is "one billion, one million, five hundred sixty-one thousand, two hundred".