1561516201 has 24 divisors (see below), whose sum is σ = 1844960832. Its totient is φ = 1294550400.

The previous prime is 1561516199. The next prime is 1561516213. The reversal of 1561516201 is 1026151651.

It is a happy number.

It is not a de Polignac number, because 1561516201 - 2¹ = 1561516199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1561516201.

It is not an unprimeable number, because it can be changed into a prime (1561511201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1540971 + ... + 1541983.

It is an arithmetic number, because the mean of its divisors is an integer number (76873368).

Almost surely, 2^1561516201 is an apocalyptic number.

It is an amenable number.

1561516201 is a deficient number, since it is larger than the sum of its proper divisors (283444631).

1561516201 is a wasteful number, since it uses less digits than its factorization.

1561516201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233 (or 1192 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 28.

The square root of 1561516201 is about 39516.0246102768. The cubic root of 1561516201 is about 1160.1536164475.

Adding to 1561516201 its reverse (1026151651), we get a palindrome (2587667852).

The spelling of 1561516201 in words is "one billion, five hundred sixty-one million, five hundred sixteen thousand, two hundred one".