1561651650051 has 4 divisors (see below), whose sum is σ = 2082202200072. Its totient is φ = 1041101100032.

The previous prime is 1561651650007. The next prime is 1561651650079. The reversal of 1561651650051 is 1500561561651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1561651650051 - 2¹⁵ = 1561651617283 is a prime.

It is a super-2 number, since 2×1561651650051² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1561651649985 and 1561651650012.

It is not an unprimeable number, because it can be changed into a prime (1561651650151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260275275006 + ... + 260275275011.

It is an arithmetic number, because the mean of its divisors is an integer number (520550550018).

Almost surely, 2^{1561651650051} is an apocalyptic number.

1561651650051 is a deficient number, since it is larger than the sum of its proper divisors (520550550021).

1561651650051 is an equidigital number, since it uses as much as digits as its factorization.

1561651650051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520550550020.

The product of its (nonzero) digits is 135000, while the sum is 42.

The spelling of 1561651650051 in words is "one trillion, five hundred sixty-one billion, six hundred fifty-one million, six hundred fifty thousand, fifty-one".