66365224570640 has 40 divisors (see below), whose sum is σ = 154335877055448. Its totient is φ = 26539770700800.

The previous prime is 66365224570583. The next prime is 66365224570643. The reversal of 66365224570640 is 4607542256366.

It can be written as a sum of positive squares in 4 ways, for example, as 3493265664784 + 62871958905856 = 1869028^2 + 7929184^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×66365224570640² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66365224570643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98398187 + ... + 99070346.

Almost surely, 2^{66365224570640} is an apocalyptic number.

It is an amenable number.

66365224570640 is an abundant number, since it is smaller than the sum of its proper divisors (87970652484808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66365224570640 is a wasteful number, since it uses less digits than its factorization.

66365224570640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197472747 (or 197472741 counting only the distinct ones).

The product of its (nonzero) digits is 43545600, while the sum is 56.

The spelling of 66365224570640 in words is "sixty-six trillion, three hundred sixty-five billion, two hundred twenty-four million, five hundred seventy thousand, six hundred forty".