661016655 has 48 divisors (see below), whose sum is σ = 1267287840. Its totient is φ = 316617984.

The previous prime is 661016641. The next prime is 661016677. The reversal of 661016655 is 556610166.

661016655 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661016655 - 2⁵ = 661016623 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6376 + ... + 36914.

It is an arithmetic number, because the mean of its divisors is an integer number (26401830).

Almost surely, 2^661016655 is an apocalyptic number.

661016655 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

661016655 is a deficient number, since it is larger than the sum of its proper divisors (606271185).

661016655 is a wasteful number, since it uses less digits than its factorization.

661016655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30600 (or 30597 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 661016655 is about 25710.2441645349. The cubic root of 661016655 is about 871.1055900686.

The spelling of 661016655 in words is "six hundred sixty-one million, sixteen thousand, six hundred fifty-five".