61043721 has 4 divisors (see below), whose sum is σ = 81391632. Its totient is φ = 40695812.

The previous prime is 61043699. The next prime is 61043779. The reversal of 61043721 is 12734016.

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 61043721 - 2¹⁵ = 61010953 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 61043691 and 61043700.

It is not an unprimeable number, because it can be changed into a prime (61043621) 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, 10173951 + ... + 10173956.

It is an arithmetic number, because the mean of its divisors is an integer number (20347908).

Almost surely, 2^61043721 is an apocalyptic number.

It is an amenable number.

61043721 is a deficient number, since it is larger than the sum of its proper divisors (20347911).

61043721 is a wasteful number, since it uses less digits than its factorization.

61043721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20347910.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 61043721 is about 7813.0481247718. The cubic root of 61043721 is about 393.7437437152.

Adding to 61043721 its reverse (12734016), we get a palindrome (73777737).

The spelling of 61043721 in words is "sixty-one million, forty-three thousand, seven hundred twenty-one".