1561533804 has 36 divisors (see below), whose sum is σ = 3951543960. Its totient is φ = 519939840.

The previous prime is 1561533803. The next prime is 1561533817. The reversal of 1561533804 is 4083351651.

1561533804 is a `hidden beast` number, since 1 + 5 + 615 + 3 + 38 + 0 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1561533803) 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, 10099 + ... + 56789.

It is an arithmetic number, because the mean of its divisors is an integer number (109765110).

Almost surely, 2^1561533804 is an apocalyptic number.

It is an amenable number.

1561533804 is an abundant number, since it is smaller than the sum of its proper divisors (2390010156).

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

1561533804 is a wasteful number, since it uses less digits than its factorization.

1561533804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47630 (or 47625 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 1561533804 is about 39516.2473420744. The cubic root of 1561533804 is about 1160.1579759086.

The spelling of 1561533804 in words is "one billion, five hundred sixty-one million, five hundred thirty-three thousand, eight hundred four".