1561722121207 has 8 divisors (see below), whose sum is σ = 1587381869312. Its totient is φ = 1536064236000.

The previous prime is 1561722121153. The next prime is 1561722121229. The reversal of 1561722121207 is 7021212271651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561722121207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561722121507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1277893 + ... + 2180929.

It is an arithmetic number, because the mean of its divisors is an integer number (198422733664).

Almost surely, 2^{1561722121207} is an apocalyptic number.

1561722121207 is a deficient number, since it is larger than the sum of its proper divisors (25659748105).

1561722121207 is an equidigital number, since it uses as much as digits as its factorization.

1561722121207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931449.

The product of its (nonzero) digits is 23520, while the sum is 37.

Adding to 1561722121207 its reverse (7021212271651), we get a palindrome (8582934392858).

The spelling of 1561722121207 in words is "one trillion, five hundred sixty-one billion, seven hundred twenty-two million, one hundred twenty-one thousand, two hundred seven".