1561215364655 has 16 divisors (see below), whose sum is σ = 1881574109184. Its totient is φ = 1243567740960.

The previous prime is 1561215364637. The next prime is 1561215364663. The reversal of 1561215364655 is 5564635121651.

It is not a de Polignac number, because 1561215364655 - 2¹⁴ = 1561215348271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1755644 + ... + 2490926.

It is an arithmetic number, because the mean of its divisors is an integer number (117598381824).

Almost surely, 2^{1561215364655} is an apocalyptic number.

1561215364655 is a deficient number, since it is larger than the sum of its proper divisors (320358744529).

1561215364655 is a wasteful number, since it uses less digits than its factorization.

1561215364655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737126.

The product of its digits is 3240000, while the sum is 50.

The spelling of 1561215364655 in words is "one trillion, five hundred sixty-one billion, two hundred fifteen million, three hundred sixty-four thousand, six hundred fifty-five".