61651688569 has 2 divisors, whose sum is σ = 61651688570. Its totient is φ = 61651688568.

The previous prime is 61651688551. The next prime is 61651688597. The reversal of 61651688569 is 96588615616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42750938169 + 18900750400 = 206763^2 + 137480^2 .

It is a cyclic number.

It is not a de Polignac number, because 61651688569 - 2⁹ = 61651688057 is a prime.

It is a super-2 number, since 2×61651688569² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61651688869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30825844284 + 30825844285.

It is an arithmetic number, because the mean of its divisors is an integer number (30825844285).

Almost surely, 2^61651688569 is an apocalyptic number.

It is an amenable number.

61651688569 is a deficient number, since it is larger than the sum of its proper divisors (1).

61651688569 is an equidigital number, since it uses as much as digits as its factorization.

61651688569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18662400, while the sum is 61.

The spelling of 61651688569 in words is "sixty-one billion, six hundred fifty-one million, six hundred eighty-eight thousand, five hundred sixty-nine".