61508661 has 4 divisors (see below), whose sum is σ = 82011552. Its totient is φ = 41005772.

The previous prime is 61508653. The next prime is 61508663. The reversal of 61508661 is 16680516.

61508661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61508661 - 2³ = 61508653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61508663) 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 3 ways as a sum of consecutive naturals, for example, 10251441 + ... + 10251446.

It is an arithmetic number, because the mean of its divisors is an integer number (20502888).

Almost surely, 2^61508661 is an apocalyptic number.

It is an amenable number.

61508661 is a deficient number, since it is larger than the sum of its proper divisors (20502891).

61508661 is a wasteful number, since it uses less digits than its factorization.

61508661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20502890.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 61508661 is about 7842.7457564300. The cubic root of 61508661 is about 394.7408672647.

The spelling of 61508661 in words is "sixty-one million, five hundred eight thousand, six hundred sixty-one".