1561217645274 has 64 divisors (see below), whose sum is σ = 3576025117440. Its totient is φ = 445121671680.

The previous prime is 1561217645261. The next prime is 1561217645279. The reversal of 1561217645274 is 4725467121651.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1561217645279) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 126623542 + ... + 126635870.

It is an arithmetic number, because the mean of its divisors is an integer number (55875392460).

Almost surely, 2^{1561217645274} is an apocalyptic number.

1561217645274 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

1561217645274 is an abundant number, since it is smaller than the sum of its proper divisors (2014807472166).

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

1561217645274 is a wasteful number, since it uses less digits than its factorization.

1561217645274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18455.

The product of its digits is 2822400, while the sum is 51.

The spelling of 1561217645274 in words is "one trillion, five hundred sixty-one billion, two hundred seventeen million, six hundred forty-five thousand, two hundred seventy-four".