661028305 has 8 divisors (see below), whose sum is σ = 906553152. Its totient is φ = 453276528.

The previous prime is 661028299. The next prime is 661028309. The reversal of 661028305 is 503820166.

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 661028305 - 2¹¹ = 661026257 is a prime.

It is a super-2 number, since 2×661028305² = 873916840022346050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661028309) 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, 9443227 + ... + 9443296.

It is an arithmetic number, because the mean of its divisors is an integer number (113319144).

Almost surely, 2^661028305 is an apocalyptic number.

It is an amenable number.

661028305 is a deficient number, since it is larger than the sum of its proper divisors (245524847).

661028305 is a wasteful number, since it uses less digits than its factorization.

661028305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18886535.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 661028305 is about 25710.4707269237. The cubic root of 661028305 is about 871.1107076001.

The spelling of 661028305 in words is "six hundred sixty-one million, twenty-eight thousand, three hundred five".