661858339 has 8 divisors (see below), whose sum is σ = 686683008. Its totient is φ = 637250880.

The previous prime is 661858321. The next prime is 661858381. The reversal of 661858339 is 933858166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661858339 - 2¹⁷ = 661727267 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661858292 and 661858301.

It is not an unprimeable number, because it can be changed into a prime (661858139) 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, 48082 + ... + 60295.

It is an arithmetic number, because the mean of its divisors is an integer number (85835376).

Almost surely, 2^661858339 is an apocalyptic number.

661858339 is a deficient number, since it is larger than the sum of its proper divisors (24824669).

661858339 is a wasteful number, since it uses less digits than its factorization.

661858339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108605.

The product of its digits is 933120, while the sum is 49.

The square root of 661858339 is about 25726.6076076890. The cubic root of 661858339 is about 871.4751645491.

The spelling of 661858339 in words is "six hundred sixty-one million, eight hundred fifty-eight thousand, three hundred thirty-nine".