66905074251 has 20 divisors (see below), whose sum is σ = 105823714392. Its totient is φ = 41979653568.

The previous prime is 66905074241. The next prime is 66905074253. The reversal of 66905074251 is 15247050966.

66905074251 is a `hidden beast` number, since 6 + 6 + 90 + 507 + 4 + 2 + 51 = 666.

It is not a de Polignac number, because 66905074251 - 2⁷ = 66905074123 is a prime.

It is a super-2 number, since 2×66905074251² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66905074197 and 66905074206.

It is not an unprimeable number, because it can be changed into a prime (66905074253) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24292405 + ... + 24295158.

Almost surely, 2^66905074251 is an apocalyptic number.

66905074251 is a deficient number, since it is larger than the sum of its proper divisors (38918640141).

66905074251 is a wasteful number, since it uses less digits than its factorization.

66905074251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48587592 (or 48587583 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 66905074251 in words is "sixty-six billion, nine hundred five million, seventy-four thousand, two hundred fifty-one".