61639252789 has 2 divisors, whose sum is σ = 61639252790. Its totient is φ = 61639252788.

The previous prime is 61639252751. The next prime is 61639252849. The reversal of 61639252789 is 98725293616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51355264689 + 10283988100 = 226617^2 + 101410^2 .

It is a cyclic number.

It is not a de Polignac number, because 61639252789 - 2¹¹ = 61639250741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61639252709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30819626394 + 30819626395.

It is an arithmetic number, because the mean of its divisors is an integer number (30819626395).

Almost surely, 2^61639252789 is an apocalyptic number.

It is an amenable number.

61639252789 is a deficient number, since it is larger than the sum of its proper divisors (1).

61639252789 is an equidigital number, since it uses as much as digits as its factorization.

61639252789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9797760, while the sum is 58.

The spelling of 61639252789 in words is "sixty-one billion, six hundred thirty-nine million, two hundred fifty-two thousand, seven hundred eighty-nine".