61212661 has 4 divisors (see below), whose sum is σ = 64434400. Its totient is φ = 57990924.

The previous prime is 61212653. The next prime is 61212691. The reversal of 61212661 is 16621216.

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 61212661 - 2³ = 61212653 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 (61212691) 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, 1610841 + ... + 1610878.

It is an arithmetic number, because the mean of its divisors is an integer number (16108600).

Almost surely, 2^61212661 is an apocalyptic number.

It is an amenable number.

61212661 is a deficient number, since it is larger than the sum of its proper divisors (3221739).

61212661 is a wasteful number, since it uses less digits than its factorization.

61212661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3221738.

The product of its digits is 864, while the sum is 25.

The square root of 61212661 is about 7823.8520563722. The cubic root of 61212661 is about 394.1066409783.

Adding to 61212661 its reverse (16621216), we get a palindrome (77833877).

The spelling of 61212661 in words is "sixty-one million, two hundred twelve thousand, six hundred sixty-one".