61003661 has 4 divisors (see below), whose sum is σ = 64214400. Its totient is φ = 57792924.

The previous prime is 61003651. The next prime is 61003673. The reversal of 61003661 is 16630016.

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 61003661 - 2¹⁸ = 60741517 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 (61003651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1605341 + ... + 1605378.

It is an arithmetic number, because the mean of its divisors is an integer number (16053600).

Almost surely, 2^61003661 is an apocalyptic number.

It is an amenable number.

61003661 is a deficient number, since it is larger than the sum of its proper divisors (3210739).

61003661 is a wasteful number, since it uses less digits than its factorization.

61003661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3210738.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 61003661 is about 7810.4840438989. The cubic root of 61003661 is about 393.6575932981.

Adding to 61003661 its reverse (16630016), we get a palindrome (77633677).

The spelling of 61003661 in words is "sixty-one million, three thousand, six hundred sixty-one".