66520651 has 8 divisors (see below), whose sum is σ = 68073984. Its totient is φ = 64973160.

The previous prime is 66520639. The next prime is 66520661. The reversal of 66520651 is 15602566.

66520651 = T₁₀₆ + T₁₀₇ + ... + T₇₃₆.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66520651 - 2¹⁷ = 66389579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66520661) 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, 28536 + ... + 30778.

It is an arithmetic number, because the mean of its divisors is an integer number (8509248).

Almost surely, 2^66520651 is an apocalyptic number.

66520651 is a deficient number, since it is larger than the sum of its proper divisors (1553333).

66520651 is a wasteful number, since it uses less digits than its factorization.

66520651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2921.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 66520651 is about 8156.0193109139. The cubic root of 66520651 is about 405.1838843884.

It can be divided in two parts, 665 and 20651, that added together give a square (21316 = 146²).

The spelling of 66520651 in words is "sixty-six million, five hundred twenty thousand, six hundred fifty-one".