661616123 has 8 divisors (see below), whose sum is σ = 756314592. Its totient is φ = 566963136.

The previous prime is 661616107. The next prime is 661616141. The reversal of 661616123 is 321616166.

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 661616123 - 2⁴ = 661616107 is a prime.

It is a super-2 number, since 2×661616123² = 875471788427102258, which contains 22 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 661616123.

It is not an unprimeable number, because it can be changed into a prime (661616143) 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, 29711 + ... + 46967.

It is an arithmetic number, because the mean of its divisors is an integer number (94539324).

Almost surely, 2^661616123 is an apocalyptic number.

661616123 is a deficient number, since it is larger than the sum of its proper divisors (94698469).

661616123 is a wasteful number, since it uses less digits than its factorization.

661616123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22741.

The product of its digits is 7776, while the sum is 32.

The square root of 661616123 is about 25721.8996771234. The cubic root of 661616123 is about 871.3688422083.

The spelling of 661616123 in words is "six hundred sixty-one million, six hundred sixteen thousand, one hundred twenty-three".