661814541 has 12 divisors (see below), whose sum is σ = 956186400. Its totient is φ = 441102600.

The previous prime is 661814509. The next prime is 661814557. The reversal of 661814541 is 145418166.

It is not a de Polignac number, because 661814541 - 2⁵ = 661814509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661814496 and 661814505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661814941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52360 + ... + 63758.

It is an arithmetic number, because the mean of its divisors is an integer number (79682200).

Almost surely, 2^661814541 is an apocalyptic number.

It is an amenable number.

661814541 is a deficient number, since it is larger than the sum of its proper divisors (294371859).

661814541 is a wasteful number, since it uses less digits than its factorization.

661814541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17856 (or 17853 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 661814541 is about 25725.7563737201. The cubic root of 661814541 is about 871.4559410441.

The spelling of 661814541 in words is "six hundred sixty-one million, eight hundred fourteen thousand, five hundred forty-one".