611215661 has 6 divisors (see below), whose sum is σ = 711006030. Its totient is φ = 523899096.

The previous prime is 611215651. The next prime is 611215667. The reversal of 611215661 is 166512116.

611215661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 400240036 + 210975625 = 20006^2 + 14525^2 .

It is not a de Polignac number, because 611215661 - 2⁶ = 611215597 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (611215667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6236846 + ... + 6236943.

It is an arithmetic number, because the mean of its divisors is an integer number (118501005).

Almost surely, 2^611215661 is an apocalyptic number.

It is an amenable number.

611215661 is a deficient number, since it is larger than the sum of its proper divisors (99790369).

611215661 is a wasteful number, since it uses less digits than its factorization.

611215661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12473803 (or 12473796 counting only the distinct ones).

The product of its digits is 2160, while the sum is 29.

The square root of 611215661 is about 24722.7761588378. The cubic root of 611215661 is about 848.6556192215.

Adding to 611215661 its reverse (166512116), we get a palindrome (777727777).

The spelling of 611215661 in words is "six hundred eleven million, two hundred fifteen thousand, six hundred sixty-one".