61251378717 has 4 divisors (see below), whose sum is σ = 81668504960. Its totient is φ = 40834252476.

The previous prime is 61251378707. The next prime is 61251378719. The reversal of 61251378717 is 71787315216.

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 de Polignac number, because none of the positive numbers 2^k-61251378717 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 (61251378719) 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, 10208563117 + ... + 10208563122.

It is an arithmetic number, because the mean of its divisors is an integer number (20417126240).

Almost surely, 2^61251378717 is an apocalyptic number.

It is an amenable number.

61251378717 is a deficient number, since it is larger than the sum of its proper divisors (20417126243).

61251378717 is a wasteful number, since it uses less digits than its factorization.

61251378717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20417126242.

The product of its digits is 493920, while the sum is 48.

The spelling of 61251378717 in words is "sixty-one billion, two hundred fifty-one million, three hundred seventy-eight thousand, seven hundred seventeen".