661520445 has 16 divisors (see below), whose sum is σ = 1084249152. Its totient is φ = 344205440.

The previous prime is 661520443. The next prime is 661520459. The reversal of 661520445 is 544025166.

It is not a de Polignac number, because 661520445 - 2¹ = 661520443 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661520443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 537207 + ... + 538436.

It is an arithmetic number, because the mean of its divisors is an integer number (67765572).

Almost surely, 2^661520445 is an apocalyptic number.

It is an amenable number.

661520445 is a deficient number, since it is larger than the sum of its proper divisors (422728707).

661520445 is a wasteful number, since it uses less digits than its factorization.

661520445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075692.

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 661520445 is about 25720.0397550237. The cubic root of 661520445 is about 871.3268365577.

The spelling of 661520445 in words is "six hundred sixty-one million, five hundred twenty thousand, four hundred forty-five".