61869722749 has 4 divisors (see below), whose sum is σ = 61870236064. Its totient is φ = 61869209436.

The previous prime is 61869722693. The next prime is 61869722767. The reversal of 61869722749 is 94722796816.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61869722749 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 (61869722449) 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, 33424 + ... + 353350.

It is an arithmetic number, because the mean of its divisors is an integer number (15467559016).

Almost surely, 2^61869722749 is an apocalyptic number.

It is an amenable number.

61869722749 is a deficient number, since it is larger than the sum of its proper divisors (513315).

61869722749 is a wasteful number, since it uses less digits than its factorization.

61869722749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513314.

The product of its digits is 18289152, while the sum is 61.

The spelling of 61869722749 in words is "sixty-one billion, eight hundred sixty-nine million, seven hundred twenty-two thousand, seven hundred forty-nine".