65061621556 has 6 divisors (see below), whose sum is σ = 113857837730. Its totient is φ = 32530810776.

The previous prime is 65061621551. The next prime is 65061621577. The reversal of 65061621556 is 65512616056.

It can be written as a sum of positive squares in only one way, i.e., 49004676900 + 16056944656 = 221370^2 + 126716^2 .

It is a super-2 number, since 2×65061621556² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65061621551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8132702691 + ... + 8132702698.

Almost surely, 2^65061621556 is an apocalyptic number.

It is an amenable number.

65061621556 is a deficient number, since it is larger than the sum of its proper divisors (48796216174).

65061621556 is a wasteful number, since it uses less digits than its factorization.

65061621556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16265405393 (or 16265405391 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 43.

The spelling of 65061621556 in words is "sixty-five billion, sixty-one million, six hundred twenty-one thousand, five hundred fifty-six".