1561655500451 has 16 divisors (see below), whose sum is σ = 1642626216000. Its totient is φ = 1481800286208.

The previous prime is 1561655500441. The next prime is 1561655500499. The reversal of 1561655500451 is 1540055561651.

It is a cyclic number.

It is not a de Polignac number, because 1561655500451 - 2⁶ = 1561655500387 is a prime.

It is a super-2 number, since 2×1561655500451² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561655500441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2339075 + ... + 2931651.

It is an arithmetic number, because the mean of its divisors is an integer number (102664138500).

Almost surely, 2^{1561655500451} is an apocalyptic number.

1561655500451 is a deficient number, since it is larger than the sum of its proper divisors (80970715549).

1561655500451 is a wasteful number, since it uses less digits than its factorization.

1561655500451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593518.

The product of its (nonzero) digits is 450000, while the sum is 44.

The spelling of 1561655500451 in words is "one trillion, five hundred sixty-one billion, six hundred fifty-five million, five hundred thousand, four hundred fifty-one".