61256830721 has 4 divisors (see below), whose sum is σ = 61263376944. Its totient is φ = 61250284500.

The previous prime is 61256830717. The next prime is 61256830729. The reversal of 61256830721 is 12703865216.

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 61256830721 - 2² = 61256830717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61256830729) 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, 3259055 + ... + 3277796.

It is an arithmetic number, because the mean of its divisors is an integer number (15315844236).

Almost surely, 2^61256830721 is an apocalyptic number.

It is an amenable number.

61256830721 is a deficient number, since it is larger than the sum of its proper divisors (6546223).

61256830721 is an equidigital number, since it uses as much as digits as its factorization.

61256830721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6546222.

The product of its (nonzero) digits is 120960, while the sum is 41.

The spelling of 61256830721 in words is "sixty-one billion, two hundred fifty-six million, eight hundred thirty thousand, seven hundred twenty-one".