66124212561 has 48 divisors (see below), whose sum is σ = 105376759488. Its totient is φ = 39621888000.

The previous prime is 66124212551. The next prime is 66124212589. The reversal of 66124212561 is 16521242166.

66124212561 is a `hidden beast` number, since 6 + 61 + 24 + 2 + 12 + 561 = 666.

It is not a de Polignac number, because 66124212561 - 2¹³ = 66124204369 is a prime.

It is a super-2 number, since 2×66124212561² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66124212551) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11395861 + ... + 11401661.

It is an arithmetic number, because the mean of its divisors is an integer number (2195349156).

Almost surely, 2^66124212561 is an apocalyptic number.

It is an amenable number.

66124212561 is a deficient number, since it is larger than the sum of its proper divisors (39252546927).

66124212561 is a wasteful number, since it uses less digits than its factorization.

66124212561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7102 (or 7099 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The spelling of 66124212561 in words is "sixty-six billion, one hundred twenty-four million, two hundred twelve thousand, five hundred sixty-one".