61638037065 has 144 divisors (see below), whose sum is σ = 122890569984. Its totient is φ = 28504270080.

The previous prime is 61638037061. The next prime is 61638037067. The reversal of 61638037065 is 56073083616.

61638037065 is a `hidden beast` number, since 6 + 1 + 638 + 0 + 3 + 7 + 0 + 6 + 5 = 666.

It is not a de Polignac number, because 61638037065 - 2² = 61638037061 is a prime.

It is a super-2 number, since 2×61638037065² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 61638037065.

It is not an unprimeable number, because it can be changed into a prime (61638037061) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 84783732 + ... + 84784458.

It is an arithmetic number, because the mean of its divisors is an integer number (853406736).

Almost surely, 2^61638037065 is an apocalyptic number.

It is an amenable number.

61638037065 is a deficient number, since it is larger than the sum of its proper divisors (61252532919).

61638037065 is a wasteful number, since it uses less digits than its factorization.

61638037065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460 (or 1446 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 61638037065 in words is "sixty-one billion, six hundred thirty-eight million, thirty-seven thousand, sixty-five".