1561501200 has 120 divisors (see below), whose sum is σ = 5716612288. Its totient is φ = 356912640.

The previous prime is 1561501199. The next prime is 1561501243. The reversal of 1561501200 is 21051651.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 84547 + ... + 101346.

Almost surely, 2^1561501200 is an apocalyptic number.

1561501200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561501200 is an abundant number, since it is smaller than the sum of its proper divisors (4155111088).

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

1561501200 is a wasteful number, since it uses less digits than its factorization.

1561501200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185921 (or 185910 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 21.

The square root of 1561501200 is about 39515.8348007479. The cubic root of 1561501200 is about 1160.1499013574.

Adding to 1561501200 its reverse (21051651), we get a palindrome (1582552851).

The spelling of 1561501200 in words is "one billion, five hundred sixty-one million, five hundred one thousand, two hundred".