1561323513655 has 8 divisors (see below), whose sum is σ = 1881052712784. Its totient is φ = 1244082480000.

The previous prime is 1561323513653. The next prime is 1561323513671. The reversal of 1561323513655 is 5563153231651.

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

It is not a de Polignac number, because 1561323513655 - 2¹ = 1561323513653 is a prime.

It is a super-2 number, since 2×1561323513655² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561323513653) 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, 622039986 + ... + 622042495.

It is an arithmetic number, because the mean of its divisors is an integer number (235131589098).

Almost surely, 2^{1561323513655} is an apocalyptic number.

1561323513655 is a deficient number, since it is larger than the sum of its proper divisors (319729199129).

1561323513655 is a wasteful number, since it uses less digits than its factorization.

1561323513655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244082737.

The product of its digits is 1215000, while the sum is 46.

The spelling of 1561323513655 in words is "one trillion, five hundred sixty-one billion, three hundred twenty-three million, five hundred thirteen thousand, six hundred fifty-five".