661116599 has 16 divisors (see below), whose sum is σ = 778788864. Its totient is φ = 553288800.

The previous prime is 661116593. The next prime is 661116611. The reversal of 661116599 is 995611166.

It is a cyclic number.

It is not a de Polignac number, because 661116599 - 2¹² = 661112503 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 (661116593) 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, 48734 + ... + 60804.

It is an arithmetic number, because the mean of its divisors is an integer number (48674304).

Almost surely, 2^661116599 is an apocalyptic number.

661116599 is a deficient number, since it is larger than the sum of its proper divisors (117672265).

661116599 is a wasteful number, since it uses less digits than its factorization.

661116599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12478.

The product of its digits is 87480, while the sum is 44.

The square root of 661116599 is about 25712.1877521148. The cubic root of 661116599 is about 871.1494908231.

The spelling of 661116599 in words is "six hundred sixty-one million, one hundred sixteen thousand, five hundred ninety-nine".