1561651550 has 12 divisors (see below), whose sum is σ = 2904671976. Its totient is φ = 624660600.

The previous prime is 1561651547. The next prime is 1561651561. The reversal of 1561651550 is 551561651.

It is a self number, because there is not a number n which added to its sum of digits gives 1561651550.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15616466 + ... + 15616565.

It is an arithmetic number, because the mean of its divisors is an integer number (242055998).

Almost surely, 2^1561651550 is an apocalyptic number.

1561651550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1561651550 is a deficient number, since it is larger than the sum of its proper divisors (1343020426).

1561651550 is a wasteful number, since it uses less digits than its factorization.

1561651550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31233043 (or 31233038 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 35.

The square root of 1561651550 is about 39517.7371568768. The cubic root of 1561651550 is about 1160.1871353857.

The spelling of 1561651550 in words is "one billion, five hundred sixty-one million, six hundred fifty-one thousand, five hundred fifty".