1561661625226 has 16 divisors (see below), whose sum is σ = 2377819540800. Its totient is φ = 769121830048.

The previous prime is 1561661625211. The next prime is 1561661625241. The reversal of 1561661625226 is 6225261661651.

It is an interprime number because it is at equal distance from previous prime (1561661625211) and next prime (1561661625241).

It is a self number, because there is not a number n which added to its sum of digits gives 1561661625226.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16632616 + ... + 16726243.

It is an arithmetic number, because the mean of its divisors is an integer number (148613721300).

Almost surely, 2^{1561661625226} is an apocalyptic number.

1561661625226 is a deficient number, since it is larger than the sum of its proper divisors (816157915574).

1561661625226 is a wasteful number, since it uses less digits than its factorization.

1561661625226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33359213.

The product of its digits is 1555200, while the sum is 49.

The spelling of 1561661625226 in words is "one trillion, five hundred sixty-one billion, six hundred sixty-one million, six hundred twenty-five thousand, two hundred twenty-six".