61016661 has 6 divisors (see below), whose sum is σ = 88135190. Its totient is φ = 40677768.

The previous prime is 61016647. The next prime is 61016707. The reversal of 61016661 is 16661016.

It can be written as a sum of positive squares in only one way, i.e., 51926436 + 9090225 = 7206^2 + 3015^2 .

It is not a de Polignac number, because 61016661 - 2⁶ = 61016597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61016161) 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, 3389806 + ... + 3389823.

Almost surely, 2^61016661 is an apocalyptic number.

It is an amenable number.

61016661 is a deficient number, since it is larger than the sum of its proper divisors (27118529).

61016661 is a wasteful number, since it uses less digits than its factorization.

61016661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6779635 (or 6779632 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 61016661 is about 7811.3162143137. The cubic root of 61016661 is about 393.6855543809.

Adding to 61016661 its reverse (16661016), we get a palindrome (77677677).

It can be divided in two parts, 610 and 16661, that added together give a palindrome (17271).

The spelling of 61016661 in words is "sixty-one million, sixteen thousand, six hundred sixty-one".