611601561 has 24 divisors (see below), whose sum is σ = 922975560. Its totient is φ = 389760000.

The previous prime is 611601559. The next prime is 611601563. The reversal of 611601561 is 165106116.

611601561 is a `hidden beast` number, since 6 + 1 + 1 + 601 + 56 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (611601559) and next prime (611601563).

It can be written as a sum of positive squares in 4 ways, for example, as 409819536 + 201782025 = 20244^2 + 14205^2 .

It is not a de Polignac number, because 611601561 - 2¹ = 611601559 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (611601563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14761 + ... + 37961.

It is an arithmetic number, because the mean of its divisors is an integer number (38457315).

Almost surely, 2^611601561 is an apocalyptic number.

It is an amenable number.

611601561 is a deficient number, since it is larger than the sum of its proper divisors (311373999).

611601561 is a wasteful number, since it uses less digits than its factorization.

611601561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23337 (or 23334 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 611601561 is about 24730.5794715773. The cubic root of 611601561 is about 848.8341853836.

Adding to 611601561 its reverse (165106116), we get a palindrome (776707677).

The spelling of 611601561 in words is "six hundred eleven million, six hundred one thousand, five hundred sixty-one".