661664616114534 has 32 divisors (see below), whose sum is σ = 1331766426167520. Its totient is φ = 219148690655232.

The previous prime is 661664616114487. The next prime is 661664616114569. The reversal of 661664616114534 is 435411616466166.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154093062 + ... + 158328774.

It is an arithmetic number, because the mean of its divisors is an integer number (41617700817735).

Almost surely, 2^{661664616114534} is an apocalyptic number.

661664616114534 is an abundant number, since it is smaller than the sum of its proper divisors (670101810052986).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661664616114534 is a wasteful number, since it uses less digits than its factorization.

661664616114534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4401704.

The product of its digits is 44789760, while the sum is 60.

The spelling of 661664616114534 in words is "six hundred sixty-one trillion, six hundred sixty-four billion, six hundred sixteen million, one hundred fourteen thousand, five hundred thirty-four".