618603661 has 4 divisors (see below), whose sum is σ = 666188572. Its totient is φ = 571018752.

The previous prime is 618603649. The next prime is 618603677. The reversal of 618603661 is 166306816.

618603661 = T₉₇₄₉ + T₉₇₅₀ + ... + T₉₇₆₁.

It is a happy number.

618603661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 128822500 + 489781161 = 11350^2 + 22131^2 .

It is a cyclic number.

It is not a de Polignac number, because 618603661 - 2⁹ = 618603149 is a prime.

It is a super-3 number, since 3×618603661³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 618603661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (618603641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23792436 + ... + 23792461.

It is an arithmetic number, because the mean of its divisors is an integer number (166547143).

Almost surely, 2^618603661 is an apocalyptic number.

It is an amenable number.

618603661 is a deficient number, since it is larger than the sum of its proper divisors (47584911).

618603661 is a wasteful number, since it uses less digits than its factorization.

618603661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47584910.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 618603661 is about 24871.7442291448. The cubic root of 618603661 is about 852.0612768825.

The spelling of 618603661 in words is "six hundred eighteen million, six hundred three thousand, six hundred sixty-one".