1563661000 has 64 divisors (see below), whose sum is σ = 3991628160. Its totient is φ = 568600000.

The previous prime is 1563660997. The next prime is 1563661009. The reversal of 1563661000 is 1663651.

It is a self number, because there is not a number n which added to its sum of digits gives 1563661000.

It is not an unprimeable number, because it can be changed into a prime (1563661009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60076 + ... + 82075.

It is an arithmetic number, because the mean of its divisors is an integer number (62369190).

Almost surely, 2^1563661000 is an apocalyptic number.

1563661000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1563661000 is an abundant number, since it is smaller than the sum of its proper divisors (2427967160).

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

1563661000 is a wasteful number, since it uses less digits than its factorization.

1563661000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142183 (or 142169 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 1563661000 is about 39543.1536425713. The cubic root of 1563661000 is about 1160.6845444281.

It can be divided in two parts, 15636 and 61000, that added together give a triangular number (76636 = T₃₉₁).

The spelling of 1563661000 in words is "one billion, five hundred sixty-three million, six hundred sixty-one thousand".