61961661 has 12 divisors (see below), whose sum is σ = 92586780. Its totient is φ = 39883200.

The previous prime is 61961659. The next prime is 61961671. The reversal of 61961661 is 16616916.

It can be written as a sum of positive squares in 2 ways, for example, as 10208025 + 51753636 = 3195^2 + 7194^2 .

It is not a de Polignac number, because 61961661 - 2¹ = 61961659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61961621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118440 + ... + 118961.

It is an arithmetic number, because the mean of its divisors is an integer number (7715565).

Almost surely, 2^61961661 is an apocalyptic number.

It is an amenable number.

61961661 is a deficient number, since it is larger than the sum of its proper divisors (30625119).

61961661 is a wasteful number, since it uses less digits than its factorization.

61961661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237436 (or 237433 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 61961661 is about 7871.5729686004. The cubic root of 61961661 is about 395.7075626376.

The spelling of 61961661 in words is "sixty-one million, nine hundred sixty-one thousand, six hundred sixty-one".