1561661345154 has 16 divisors (see below), whose sum is σ = 3136282538400. Its totient is φ = 518393807040.

The previous prime is 1561661345149. The next prime is 1561661345159. The reversal of 1561661345154 is 4515431661651.

It is an interprime number because it is at equal distance from previous prime (1561661345149) and next prime (1561661345159).

It is not an unprimeable number, because it can be changed into a prime (1561661345159) 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, 539992104 + ... + 539994995.

It is an arithmetic number, because the mean of its divisors is an integer number (196017658650).

Almost surely, 2^{1561661345154} is an apocalyptic number.

1561661345154 is an abundant number, since it is smaller than the sum of its proper divisors (1574621193246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561661345154 is a wasteful number, since it uses less digits than its factorization.

1561661345154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079987345.

The product of its digits is 1296000, while the sum is 48.

The spelling of 1561661345154 in words is "one trillion, five hundred sixty-one billion, six hundred sixty-one million, three hundred forty-five thousand, one hundred fifty-four".