661416305 has 16 divisors (see below), whose sum is σ = 886975488. Its totient is φ = 469296000.

The previous prime is 661416269. The next prime is 661416307. The reversal of 661416305 is 503614166.

It is not a de Polignac number, because 661416305 - 2²⁴ = 644639089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661416307) 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, 144401 + ... + 148910.

It is an arithmetic number, because the mean of its divisors is an integer number (55435968).

Almost surely, 2^661416305 is an apocalyptic number.

It is an amenable number.

661416305 is a deficient number, since it is larger than the sum of its proper divisors (225559183).

661416305 is a wasteful number, since it uses less digits than its factorization.

661416305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293368.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 661416305 is about 25718.0151839134. The cubic root of 661416305 is about 871.2811112192.

The spelling of 661416305 in words is "six hundred sixty-one million, four hundred sixteen thousand, three hundred five".