1561166400 has 336 divisors, whose sum is σ = 5442508800. Its totient is φ = 390973440.

The previous prime is 1561166371. The next prime is 1561166441. The reversal of 1561166400 is 46611651.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8721511 + ... + 8721689.

Almost surely, 2^1561166400 is an apocalyptic number.

1561166400 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 1561166400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2721254400).

1561166400 is an abundant number, since it is smaller than the sum of its proper divisors (3881342400).

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

1561166400 is a wasteful number, since it uses less digits than its factorization.

1561166400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 1561166400 is about 39511.5982972089. The cubic root of 1561166400 is about 1160.0669798819.

The spelling of 1561166400 in words is "one billion, five hundred sixty-one million, one hundred sixty-six thousand, four hundred".