618101561 has 16 divisors (see below), whose sum is σ = 773867520. Its totient is φ = 479608080.

The previous prime is 618101551. The next prime is 618101567. The reversal of 618101561 is 165101816.

It is not a de Polignac number, because 618101561 - 2²⁶ = 550992697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (618101567) 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, 1610 + ... + 35196.

It is an arithmetic number, because the mean of its divisors is an integer number (48366720).

Almost surely, 2^618101561 is an apocalyptic number.

It is an amenable number.

618101561 is a deficient number, since it is larger than the sum of its proper divisors (155765959).

618101561 is a wasteful number, since it uses less digits than its factorization.

618101561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33844.

The product of its (nonzero) digits is 1440, while the sum is 29.

The square root of 618101561 is about 24861.6483966772. The cubic root of 618101561 is about 851.8306845580.

The spelling of 618101561 in words is "six hundred eighteen million, one hundred one thousand, five hundred sixty-one".