66535251 has 32 divisors (see below), whose sum is σ = 98219520. Its totient is φ = 39916800.

The previous prime is 66535241. The next prime is 66535253. The reversal of 66535251 is 15253566.

It is not a de Polignac number, because 66535251 - 2¹⁰ = 66534227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66535253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 81636 + ... + 82446.

It is an arithmetic number, because the mean of its divisors is an integer number (3069360).

Almost surely, 2^66535251 is an apocalyptic number.

66535251 is a deficient number, since it is larger than the sum of its proper divisors (31684269).

66535251 is a wasteful number, since it uses less digits than its factorization.

66535251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907.

The product of its digits is 27000, while the sum is 33.

The square root of 66535251 is about 8156.9143062803. The cubic root of 66535251 is about 405.2135255694.

The spelling of 66535251 in words is "sixty-six million, five hundred thirty-five thousand, two hundred fifty-one".