520651661 has 16 divisors (see below), whose sum is σ = 564493440. Its totient is φ = 478586880.

The previous prime is 520651657. The next prime is 520651711. The reversal of 520651661 is 166156025.

It is a cyclic number.

It is not a de Polignac number, because 520651661 - 2² = 520651657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520651601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148616 + ... + 152078.

It is an arithmetic number, because the mean of its divisors is an integer number (35280840).

Almost surely, 2^520651661 is an apocalyptic number.

It is an amenable number.

520651661 is a deficient number, since it is larger than the sum of its proper divisors (43841779).

520651661 is a wasteful number, since it uses less digits than its factorization.

520651661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3716.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 520651661 is about 22817.7926408318. The cubic root of 520651661 is about 804.4809281808.

The spelling of 520651661 in words is "five hundred twenty million, six hundred fifty-one thousand, six hundred sixty-one".